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Redundancy and Multihoming Using MC-LAG

 

Multichassis link aggregation (MC-LAG) enables an MX Series 5G Universal Routing Platform to form a logical LAG interface with two or more other devices. MC-LAG provides additional benefits over traditional LAG in terms of node level redundancy, multihoming support, and a loop-free Layer 2 network without the need to run Spanning Tree Protocol (STP). MC-LAG can be configured for virtual private LAN service (VPLS) routing instances, circuit cross-connect (CCC) applications, and Layer 2 circuit encapsulation types.

The MC-LAG devices use Inter-Chassis Control Protocol (ICCP) to exchange the control information between two MC-LAG network devices.

On one end of the MC-LAG is an MC-LAG client device that has one or more physical links in a link aggregation group (LAG). This client device does not need to be aware of the MC-LAG configuration. On the other side of the MC-LAG are two MC-LAG network devices. Each of these network devices has one or more physical links connected to a single client device. The network devices coordinate with each other to ensure that data traffic is forwarded properly.

MC-LAG includes the following functionality:

  • Only single-active MC-LAG mode with multi-homed VPLS instance is supported.

  • MC-LAG operates only between two devices.

  • Layer 2 circuit functions are supported with ether-ccc and vlan-ccc encapsulations.

  • VPLS functions are supported with ether-vpls and vlan-vpls encapsulations.

Note

Ethernet connectivity fault management (CFM) specified in the IEEE 802.1ag standard for Operation, Administration, and Management (OAM) is not supported on MC-LAG interfaces.

To enable MC-LAG, include the mc-ae statement at the [edit interfaces aeX aggregated-ether-options] hierarchy level along with one of the following statements at the [edit interfaces aeX] hierarchy level: encapsulation-ethernet-bridge, encapsulation ethernet-ccc, encapsulation ethernet-vpls, or encapsulation-flexible-ethernet-services. You also need to configure the lacp, admin-key, and system-id statements at the [edit interfaces aeX aggregated-ether-options] hierarchy level:

Note

When you configure the prefer-status-control-active statement, you must also configure the status-control active statement. If you configure the status-control standby statement with the prefer-status-control-active statement, the system issues a warning.

To delete an MC-LAG interface from the configuration, issue the delete interfaces aeX aggregated-ether-options mc-ae command at the [edit] hierarchy level in configuration mode:

Perform the following steps on each switch that is hosting an MC-LAG:

  1. Specify the same multichassis aggregated Ethernet identification number for the MC-LAG that the aggregated Ethernet interface belongs to on each switch.
    [edit interfaces]

    user@host# set aeX aggregated-ether-options mc-ae mc-ae-id mc-ae-id

    For example:

    [edit interfaces]

    user@host# set ae1 aggregated-ether-options mc-ae mc-ae-id 3
  2. Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to on each switch.
    [edit interfaces]

    user@host# set aeX aggregated-ether-options chassis-id chassis-id

    For example:

    [edit interfaces]

    user@host# set ae1 aggregated-ether-options mc-ae chassis-id 0
  3. Specify the mode of the MC-LAG that the aggregated Ethernet interface belongs to.Note

    Only active/active mode is supported for Reverse Layer 2 Gateway Protocol (R-L2GP) at this time.

    [edit interfaces]

    user@host# set aeX aggregated-ether-options mc-ae mode mode

    For example:

    [edit interfaces]

    user@host# set ae1 aggregated-ether-options mc-ae mode active-active
  4. Specify whether the aggregated Ethernet interface participating in the MC-LAG is primary or secondary. Primary is active, and secondary is standby.Note

    You must configure status control on both switches hosting the MC-LAG. If one switch is in active mode, the other must be in standby mode.

    [edit interfaces]

    user@host# set aeX aggregated-ether-options mc-ae status-control (active | standby)

    For example:

    [edit interfaces]

    user@host# set aeX aggregated-ether-options mc-ae status-control (active | standby)
  5. Configure the MC-LAG interface to improve Layer 2 and Layer 3 convergence time when a multichassis aggregated Ethernet link goes down or comes up in a bridge domain.
    [edit interfaces]

    user@host# set aeX aggregated-ether-options mc-ae enhanced-convergence
  6. Specify the same LACP system ID on each switch.
    [edit interfaces]

    user@host# set aeX aggregated-ether-options lacp system-id mac-address

    For example:

    [edit interfaces]

    user@host# set ae1 aggregated-ether-options lacp system-id 00:01:02:03:04:05
  7. Specify the same LACP administration key on each switch.
    [edit interfaces]

    user@host# set aeX aggregated-ether-options lacp admin-key number

    For example:

    [edit interfaces]

    user@host# set ae1 aggregated-ether-options lacp admin-key 3
  8. Configure ICCP by doing the following on each switch hosting the MC-LAG:
    1. Configure the local IP address to be used by all switches hosting the MC-LAG.
      [edit protocols]

      user@host# set iccp local-ip-addr local-ip-address

      For example:

      [edit protocols]

      user@host# set iccp local-ip-addr 10.3.3.1
    2. (Optional) Configure the IP address of the router and the time during which an ICCP connection must succeed between the routers hosting the MC-LAG.Note

      On QFX and EX Series switches, the default session establishment hold time is 300 seconds. However, the session establishment time must be at least 100 seconds higher than the init delay time. You can optionally update the session establishment time to be 340 seconds and the init delay time to be 240 seconds.

      [edit protocols]

      user@host# set iccp peer peer-ip-address session-establishment-hold-time seconds

      For example:

      [edit protocols]

      user@host# set iccp peer 10.3.3.2 session-establishment-hold-time 340
    3. (Optional) Configure the IP address to be used for backup liveness detection:Note

      By default, backup liveness detection is not enabled. Configure backup liveness detection if you require faster failover of data traffic loss during an MC-LAG peer reboot. Backup liveness detection helps achieve subsecond traffic loss during an MC-LAG peer reboot.

      [edit protocols]

      user@host# set iccp peer peer-ip-address backup-liveness-detection backup-peer-ip ip-address

      For example:

      [edit protocols]

      user@host# set iccp peer 10.3.3.2 backup-liveness-detection backup-peer-ip 10.207.64.232
    4. Configure the minimum interval at which the router must receive a reply from the other router with which it has established a Bidirectional Forwarding Detection (BFD) session.Note

      Configuring the minimum receive interval is required to enable BFD.

      [edit protocols]

      user@host# set iccp peer peer-ip-address liveness-detection minimum-receive-interval milliseconds

      For example:

      [edit protocols]

      user@host# set iccp peer 10.3.3.2 liveness-detection minimum-receive-interval 60
    5. Configure the minimum transmit interval during which a router must receive a reply from a router with which it has established a BFD session.
      [edit protocols]

      user@host# set iccp peer peer-ip-address liveness-detection transmit-interval minimum-interval milliseconds

      For example:

      [edit protocols]

      user@host# set iccp peer 10.3.3.2 liveness-detection transmit-interval minimum-interval 60
    6. Specify the switch service ID.

      The switch service ID is used to synchronize applications, IGMP, ARP, and MAC learning across MC-LAG members.

      [edit switch-options]
      user@host# set service-id number

      For example:

      [edit switch-options]
      user@host# set service-id 1
  9. Configure a multichassis protection link between the routers.
    [edit]

    user@host# set multi-chassis multi-chassis-protection peer-ip-address interface interface-name

    For example:

    [edit]

    user@host# set multi-chassis multi-chassis-protection 10.3.3.1 interface ae0
  10. Enable RSTP globally on all interfaces.
    [edit]

    user@host# set protocols rstp interface all mode point-to-point
  11. Disable RSTP on the interchassis control link protection link (ICL-PL) interfaces on both routers.
    [edit]

    user@host# set protocols rstp interface interface-name disable

    For example:

    [edit]

    user@host# set protocols rstp interface ae0.0 disable
  12. Configure the MC-LAG interfaces as edge ports on both routers.
    user@host# set protocols rstp interface interface-name edge

    For example:

    [edit]

    user@host# set protocols rstp interface ae1 edge
  13. Enable BPDU block on all interfaces except for the ICL-PL interfaces on both routers.
    [edit]

    user@host# set protocols rstp bpdu-block-on-edge

    For example:

    [edit]

    user@host# set protocols rstp bpdu-block-on-edge

Multichassis link aggregation groups (MC-LAGs) enable a client device to form a logical LAG interface between two MC-LAG peers (for example, EX9200 switches). An MC-LAG provides redundancy and load balancing between the two MC-LAG peers, multihoming support, and a loop-free Layer 2 network without running Spanning Tree Protocol (STP).

On one end of an MC-LAG, there is an MC-LAG client device, such as a server, that has one or more physical links in a link aggregation group (LAG). This client device does not need to have an MC-LAG configured. On the other side of MC-LAG, there are two MC-LAG peers. Each of the MC-LAG peers has one or more physical links connected to a single client device.

The MC-LAG peers use Inter-Chassis Control Protocol (ICCP) to exchange control information and coordinate with each other to ensure that data traffic is forwarded properly.

Note

An interface with an already configured IP address cannot form part of the aggregated Ethernet interface or multichassis aggregated Ethernet interface group.

Perform the following steps on each switch that hosts an MC-LAG:

  1. Specify the same multichassis aggregated Ethernet identification number for the MC-LAG that the aggregated Ethernet interface belongs to on each switch.
    [edit interfaces]

    user@switch# set aex aggregated-ether-options mc-ae mc-ae-id number

    For example:

    [edit interfaces]

    user@switch# set ae1 aggregated-ether-options mc-ae mc-ae-id 3
  2. Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to on each switch.
    [edit interfaces]

    user@switch# set aex aggregated-ether-options mc-ae chassis-id number

    For example:

    [edit interfaces]

    user@switch# set ae1 aggregated-ether-options mc-ae chassis-id 0
  3. Specify the mode of the MC-LAG the aggregated Ethernet interface belongs to.
    [edit interfaces]

    user@switch# set aex aggregated-ether-options mc-ae mode mode

    For example:

    [edit interfaces]

    user@switch# set ae1 aggregated-ether-options mc-ae mode active-active
  4. Specify whether the aggregated Ethernet interface participating in the MC-LAG is primary or secondary.

    Primary is active, and secondary is standby.

    Note

    You must configure status control on both switches that host the MC-LAG. If one switch is in active mode, the other must be in standby mode.

    [edit interfaces]

    user@switch# set aex aggregated-ether-options mc-ae status-control (active | standby)

    For example:

    [edit interfaces]

    user@switch# set ae1 aggregated-ether-options mc-ae status-control active
    Note

    If you configure both nodes as prefer-status-control-active, you must also configure ICCP peering using the peer’s loopback address to make sure that the ICCP session does not go down because of physical link failures. Additionally, you must configure backup liveness detection on both of the MC-LAG nodes.

    Note

    On EX9200 switches, the prefer-status-control-active statement was added in Junos OS Release 13.2R1.

  5. Specify the init delay time.

    The init delay time specifies the number of seconds by which to delay bringing up the MC-LAG interface back to the up state when the MC-LAG peer is rebooted. By delaying the bring-up of the interface until after the protocol convergence, you can prevent packet loss during the recovery of failed links and devices.

    Note

    On QFX and EX Series switches, the default session establishment hold time is 300 seconds. However, the session establishment time must be at least 100 seconds higher than the init delay time. You can optionally update the session establishment time to be 340 seconds and the init delay time to be 240 seconds.

    [edit interfaces]

    user@switch# set aex aggregated-ether-options mc-ae init-delay-time seconds

    For example:

    [edit interfaces]

    user@switch# set ae0 aggregated-ether-options mc-ae init-delay-time 240
  6. Specify the same LACP system ID on each switch.
    [edit interfaces]

    user@switch# set aex aggregated-ether-options lacp system-id mac-address

    For example:

    [edit interfaces]

    user@switch# set ae1 aggregated-ether-options lacp system-id 00:01:02:03:04:05
  7. Specify the same LACP administration key on each switch.
    [edit interfaces]

    user@switch# set aex aggregated-ether-options lacp admin-key number

    For example:

    [edit interfaces]

    user@switch# set ae1 aggregated-ether-options lacp admin-key 3
  8. Configure ICCP by performing the following steps on each switch that hosts the MC-LAG:
    1. Configure the local IP address to be used by the switches that host the MC-LAG.
      [edit protocols]

      user@switch# set iccp local-ip-addr local-ip-address

      For example:

      [edit protocols]

      user@switch# set iccp local-ip-addr 10.3.3.1
    2. (Optional) Configure the IP address of the switch and the time during which an ICCP connection must be established between the switches that host the MC-LAG.Note

      On QFX and EX Series switches, the default session establishment hold time is 300 seconds. However, the session establishment time must be at least 100 seconds higher than the init delay time. You can optionally update the session establishment time to be 340 seconds and the init delay time to be 240 seconds.

      [edit protocols]

      user@switch# set iccp peer peer-ip-address session-establishment-hold-time seconds

      For example:

      [edit protocols]

      user@switch# set iccp peer 10.3.3.2 session-establishment-hold-time 340
    3. (Optional) Configure the backup-liveness-detection statement on the management interface (fxp0) only.

      We recommend that you configure the backup liveness detection feature to implement faster failover of data traffic during an MC-LAG peer reboot.

      Note

      On EX9200 switches, the backup-liveness-detection statement was added in Junos OS Release 13.2R1.

      Note

      By default, backup liveness detection is not enabled. Configure backup liveness detection if you require minimal traffic loss during a reboot. Backup liveness detection helps achieve sub-second traffic loss during an MC-LAG reboot.

      [edit protocols]

      user@switch# set iccp peer peer-ip-address backup-liveness-detection backup-peer-ip ip-address

      For example:

      [edit protocols]

      user@switch# set iccp peer 10.3.3.2 backup-liveness-detection backup-peer-ip 10.207.64.232
    4. Configure the minimum interval at which the switch must receive a reply from the other switch with which it has established a Bidirectional Forwarding Detection (BFD) session.Note

      Configuring the minimum receive interval is required to enable BFD. We recommend a minimum receive interval value of 1000 seconds.

      [edit protocols]

      user@switch# set iccp peer peer-ip-address liveness-detection minimum-receive-interval milliseconds

      For example:

      [edit protocols]

      user@switch# set iccp peer 10.3.3.2 liveness-detection minimum-receive-interval 1000
    5. Configure the minimum transmit interval during which a switch must receive a reply from a switch with which it has established a BFD session.
      [edit protocols]

      user@switch# set iccp peer peer-ip-address liveness-detection transmit-interval minimum-interval milliseconds

      For example:

      [edit protocols]

      user@switch# set iccp peer 10.3.3.2 liveness-detection transmit-interval minimum-interval 1000
  9. Specify the switch service ID.

    The switch service ID is used to synchronize applications, IGMP, ARP, and MAC learning across MC-LAG members.

    [edit switch-options]
    user@switch# set service-id number

    For example:

    [edit switch-options]
    user@switch# set service-id 1
  10. Configure a multichassis protection link between the switches.
    [edit multi-chassis]

    user@switch# set multi-chassis-protection peer-ip-address interface interface-name

    For example:

    [edit multi-chassis]

    user@switch# set multi-chassis-protection 10.3.3.1 interface ae0

In an MC-LAG network, an MC-LAG client link without Link Access Control Protocol (LACP) configuration remains down and cannot be accessed by the MC-LAG switches.

To ensure that the client device with limited LACP capability is up and accessible on the MC-LAG network, configure one of the aggregated Ethernet links or interfaces on a MC-LAG switch to be up by using the force-up statement at the appropriate hierarchy level on your device:

  • [edit interfaces interface-name aggregated-ether-options lacp]

  • [edit interfaces interface-name ether-options 802.3ad lacp]

You can configure the force-up feature on the MC-LAG switches in either active mode or standby mode. However, in order to prevent duplicate traffic and packet drops, you configure the force-up feature only on one aggregated Ethernet link of the MC-LAG switches . If multiple aggregated Ethernet links are up on the MC-LAG switches with force-up feature configured, then the device selects the link based on the LACP port ID and port priority. The port with the lowest priority is given preference. In case of two ports with the same priority, the one with the lowest port ID is given preference.

Note

The force-up option is not supported on QFX10002 switches.

Note

On the QFX5100 switch, you can configure the force-up feature in Link Aggregation Control Protocol (LACP) on the MC-LAG switches starting with Junos OS Release 14.1X53-D10.

Note
  • If LACP comes up partially in the MC-LAG network—that is, it comes up on one of the MC-LAG switches and does not comes up on other MC-LAG switches—the force-up feature is disabled.

This example shows how multichassis link aggregation groups (MC-LAGs) enable a client device to form a logical LAG interface between two switches to provide redundancy and load balancing between the two switches, multihoming support, and a loop-free Layer 2 network without running Spanning Tree Protocol (STP).

Requirements

This example uses the following hardware and software components:

  • Junos OS Release 13.2X51-D10 or later for the QFX5100 standalone switches, Release 15.1X53-D10 or later for QFX10002 standalone switches.

    • Revalidated on Junos OS Release 17.3R1 for QFX5100 and QFX10000 switches.

Before you configure an MC-LAG, be sure that you understand how to:

Overview

In this example, you configure an MC-LAG across two switches, consisting of two aggregated Ethernet interfaces, an interchassis control link-protection link (ICL-PL), multichassis protection link for the ICL-PL, the Inter-Chassis Control Protocol for the peers hosting the MC-LAG, and Layer 3 connectivity between MC-LAG peers. Layer 3 connectivity is required for ICCP.

Topology

The topology used in this example consists of two switches hosting an MC-LAG. The two switches are connected to a server. Figure 1 shows the topology used in this example.

Figure 1: Configuring a Multichassis LAG Between Switch A and Switch B
Configuring a Multichassis LAG Between
Switch A and Switch B

Table 1 details the topology used in this configuration example.

Table 1: Components of the Topology for Configuring a Multichassis LAG Between Two Switches

HostnameBase HardwareMultichassis Link Aggregation Group

Switch A

Switch B

QFX5100 or QFX10000 series standalone switch

QFX5100 or QFX10000 series standalone switch

ae0 is configured as an aggregated Ethernet interface, and is used as an ICL-PL. The following interfaces are part of ae0: xe-0/0/12 and xe-0/0/13 Switch A and

xe-0/0/12 and xe-0/0/13 on Switch B.

ae1 is configured as an MC-LAG, and the following two interfaces are part of ae1:

xe-0/0/44 on Switch A and

xe-0/0/46 on Switch B.

.

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them in a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Switch A

set chassis aggregated-devices ethernet device-count 2
set interfaces xe-0/0/12 ether-options 802.3ad ae0
set interfaces xe-0/0/13 ether-options 802.3ad ae0
set interfaces xe-0/0/44 ether-options 802.3ad ae1
set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae0 unit 0 family ethernet-switching vlan members v500
set interfaces ae1 aggregated-ether-options lacp active
set interfaces ae1 aggregated-ether-options lacp system-id 00:01:02:03:04:05
set interfaces ae1 aggregated-ether-options lacp admin-key 3
set interfaces ae1 aggregated-ether-options mc-ae mc-ae-id 3
set interfaces ae1 aggregated-ether-options mc-ae chassis-id 0
set interfaces ae1 aggregated-ether-options mc-ae mode active-active
set interfaces ae1 aggregated-ether-options mc-ae status-control active
set interfaces ae1 aggregated-ether-options mc-ae init-delay-time 240
set interfaces ae1 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae1 unit 0 family ethernet-switching vlan members v100
set interfaces irb unit 500 family inet address 3.3.3.2/24
set vlans v100 vlan-id 100
set vlans v500 vlan-id 500
set vlans v500 l3-interface irb.500
set protocols iccp local-ip-addr 3.3.3.2
set protocols iccp peer 3.3.3.1 session-establishment-hold-time 50
set protocols iccp peer 3.3.3.1 backup-liveness-detection backup-peer-ip 10.207.64.233
set protocols iccp peer 3.3.3.1 liveness-detection minimum-receive-interval 60
set protocols iccp peer 3.3.3.1 liveness-detection transmit-interval minimum-interval 60
set protocols iccp peer 3.3.3.1 redundancy-group-id-list 1
set protocols rstp interface ae0 disable
set protocols rstp interface ae1 edge
set protocols rstp interface all mode point-to-point
set protocols rstp bpdu-block-on-edge
set multi-chassis multi-chassis-protection 3.3.3.1 interface ae0
set switch-options service-id 10

Switch B

set chassis aggregated-devices ethernet device-count 2
set interfaces xe-0/0/12 ether-options 802.3ad ae0
set interfaces xe-0/0/13 ether-options 802.3ad ae0
set interfaces xe-0/0/46 ether-options 802.3ad ae1
set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae0 unit 0 family ethernet-switching vlan members v500
set interfaces ae1 aggregated-ether-options lacp active
set interfaces ae1 aggregated-ether-options lacp system-id 00:01:02:03:04:05
set interfaces ae1 aggregated-ether-options lacp admin-key 3
set interfaces ae1 aggregated-ether-options mc-ae mc-ae-id 3
set interfaces ae1 aggregated-ether-options mc-ae chassis-id 1
set interfaces ae1 aggregated-ether-options mc-ae mode active-active
set interfaces ae1 aggregated-ether-options mc-ae status-control standby
set interfaces ae1 aggregated-ether-options mc-ae init-delay-time 240
set interfaces ae1 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae1 unit 0 family ethernet-switching vlan members v100
set interfaces irb unit 500 family inet address 3.3.3.1/24
set vlans v100 vlan-id 100
set vlans v500 vlan-id 500
set vlans v500 l3-interface irb.500
set protocols iccp local-ip-addr 3.3.3.1
set protocols iccp peer 3.3.3.2 session-establishment-hold-time 50
set protocols iccp peer 3.3.3.2 backup-liveness-detection backup-peer-ip 10.207.64.233
set protocols iccp peer 3.3.3.2 liveness-detection minimum-receive-interval 60
set protocols iccp peer 3.3.3.2 liveness-detection transmit-interval minimum-interval 60
set protocols iccp peer 3.3.3.2 redundancy-group-id-list 1
set protocols rstp interface ae0 disable
set protocols rstp interface ae1 edge
set protocols rstp interface all mode point-to-point
set protocols rstp bpdu-block-on-edge
set multi-chassis multi-chassis-protection 3.3.3.2 interface ae0
set switch-options service-id 10

Configuring MC-LAG on Two Switches

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode.

To enable multichassis protection link between MC-LAG peers:

  1. Configure the number of LAGs on both Switch A and Switch B.
  2. Add member interfaces to the aggregated Ethernet interfaces on both Switch A and Switch B.

    Switch A and Switch B:

    Switch A:

    Switch B:

  3. Configure a trunk interface between Switch A and Switch B.
  4. Configure a multichassis protection link between Switch A and Switch B.

    Switch A:

    Switch B:

Step-by-Step Procedure

To enable ICCP:

  1. Configure the local IP address to be in the ICCP connection on Switch A and Switch B.

    Switch A:

    Switch B:

  2. Configure the peer IP address and minimum receive interval for a BFD session for ICCP on Switch A and Switch B.

    Switch A:

    Switch B:

  3. Configure the peer IP address and minimum transmit interval for BFD session for ICCP on Switch A and Switch B.

    Switch A:

    Switch B:

  4. Configure the redundancy groups for ICCP on Switch A and Switch B.

    Switch A:

    Switch B:

  5. (Optional) Configure the time during which an ICCP connection must succeed between MC-LAG peers on Switch A and Switch B.Note

    Configuring session establishment hold time helps in faster ICCP connection establishment. The recommended value is 50 seconds.

    Switch A:

    Switch B:

  6. (Optional) Configure the backup IP address to be used for backup liveness detection on both Switch A and Switch B.Note

    By default, backup liveness detection is not enabled. Configuring a backup IP address helps achieve sub-second traffic loss during an MC-LAG peer reboot.

    Switch A:

    Switch B:

  7. Configure Layer 3 connectivity between the MC-LAG peers on both Switch A and Switch B.

Step-by-Step Procedure

To enable the MC-LAG interface:

  1. Enable LACP on the MC-LAG interface on Switch A and Switch B.Note

    At least one end needs to be active. The other end can be either active or passive.

  2. Specify the same multichassis aggregated Ethernet identification number on both MC-LAG peers on Switch A and Switch B.
  3. Specify a unique chassis ID for the MC-LAG on the MC-LAG peers on Switch A and Switch B.

    Switch A:

    Switch B:

  4. Specify the operating mode of the MC-LAG on both Switch A and Switch B.Note

    Only active-active mode is supported at this time.

  5. Specify the status control for MC-LAG on Switch A and Switch B.Note

    You must configure status control on both Switch A and Switch B hosting the MC-LAG. If one peer is in active mode, the other must be in standby mode.

    Switch A:

    Switch B:

  6. Specify the number of seconds by which the bring-up of the multichassis aggregated Ethernet interface should be deferred after you reboot Switch A and Switch B.Note

    The recommended value for maximum VLAN configuration (for example, 4,000 VLANS) is 240 seconds. If IGMP snooping is enabled on all of the VLANs, the recommended value is 420 seconds.

  7. Specify the same LACP system ID for the MC-LAG on Switch A and Switch B.
  8. Specify the same LACP administration key on both Switch A and Switch B.
  9. Enable VLANs on the MC-LAG on Switch A and Switch B.
  10. (Optional) Enable a private VLAN on the MC-LAG on Switch A and Switch B.

Step-by-Step Procedure

To enable RSTP:

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode.

  1. Enable RSTP globally on all interfaces on Switch A and Switch B.
  2. Disable RSTP on the ICL-PL interfaces on Switch A and Switch B:
  3. Configure the MC-LAG interfaces as edge ports on Switch A and Switch B.Note

    The ae1 interface is a downstream interface. This is why RSTP and bpdu-block-on-edge need to be configured. MC LAG switches are usually configured as root bridge. When downstream switches send superior BPDUs to the MC LAG switches, the MC LAG interfaces will be set as blocked by the downstream switches. The default behavior for the original CLI is to drop superior BPDUs.

  4. Enable BPDU blocking on all interfaces except for the ICL-PL interfaces on Switch A and Switch B.Note

    The ae1 interface is a downstream interface. This is why RSTP and bpdu-block-on-edge need to be configured.

Step-by-Step Procedure

To enable the service ID on Switch A and Switch B:

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode.

The switch service ID is used to synchronize applications, IGMP, ARP, and MAC learning across MC-LAG members.

Results

Here are the results of your configuration on Switch A.

Switch A

Switch B

Verification

Verify that the configuration is working properly.

Verifying That ICCP Is Working on Switch A

Purpose

Verify that ICCP is running on Switch A.

Action

[edit]

user@switch> show iccp

Meaning

This output shows that the TCP connection between the peers hosting the MC-LAG is up, liveness detection is up, and MCSNOOPD and ESWD client applications are running.

Verifying That ICCP Is Working on Switch B

Purpose

Verify that ICCP is running on Switch B.

Action

show iccp

[edit]

user@switch> show iccp

Meaning

This output shows that the TCP connection between the peers hosting the MC-LAG is up, liveness detection is up, and MCSNOOPD and ESWD client applications are running.

Verifying That LACP Is Active on Switch A

Purpose

Verify that LACP is active on Switch A.

Action

[edit]

user@switch> show lacp interfaces

Meaning

This output shows that Switch A is participating in LACP negotiation.

Verifying That LACP Is Active on Switch B

Purpose

Verify that LACP is active on Switch B

Action

[edit]

user@switch> show lacp interfaces

Meaning

This output shows that Switch B is participating in LACP negotiation.

Verifying That the MC-AE and ICL-PL Interfaces Are Up on Switch A

Purpose

Verify that the MC-AE and ICL-PL interfaces are up on Switch A

Action

[edit]

user@switch> show interfaces mc-ae

Meaning

This output shows that the MC-AE interface on Switch A is up and active.

Verifying That the MC-AE and ICL-PL Interfaces Are Up on Switch B

Purpose

Verify that the MC-AE and ICL-PL interfaces are up on Switch B.

Action

[edit]

user@switch> show interfaces mc-ae

Meaning

This output shows that the MC-AE interface on Switch B is up and active.

Verifying That MAC Learning Is Occurring on Switch A

Purpose

Verify that MAC learning is working on Switch A.

Action

[edit]

user@switch> show ethernet-switching table

Meaning

The output shows four learned MAC addresses entries.

Verifying That MAC Learning Is Occurring on Switch B

Purpose

Verify that MAC learning is working on Switch B.

Action

[edit]

user@switch> show ethernet-switching table

Meaning

The output shows four learned MAC addresses entries.

Troubleshooting

Troubleshooting a LAG That Is Down

Problem

The show interfaces terse command shows that the MC-LAG is down.

Solution

Check the following:

  1. Verify that there is no configuration mismatch.

  2. Verify that all member ports are up.

  3. Verify that the MC-LAG is part of family Ethernet switching (Layer 2 LAG).

  4. Verify that the MC-LAG member is connected to the correct MC-LAG member at the other end.

MC-LAG in a campus configuration allows you to bond two or more physical links into a logical link between core-aggregation or aggregation-access switches. MC-LAG improves availability by providing active/active links between multiple switches over a standard Link Aggregation Group (LAG), eliminates the need for the Spanning Tree Protocol (STP), and provides faster Layer 2 convergence upon link and device failures. With multiple active network paths, MC-LAG enables you to load balance traffic across the multiple physical links. If a link fails, the traffic can be forwarded through the other available links and the aggregated link remains available.

Requirements

This example uses the following hardware and software components:

  • Junos OS Release 13.2R5.10 for EX Series

  • Two EX9200 switches

Note

This configuration example has been tested using the software release listed and is assumed to work on all later releases.

Before you configure an MC-LAG, be sure that you understand how to:

Overview

In this example, you configure an MC-LAG across two switches, consisting of two aggregated Ethernet interfaces, an interchassis link-protection link (ICL-PL), multichassis protection link for the ICL-PL, ICCP for the peers hosting the MC-LAG, and Layer 3 connectivity between MC-LAG peers. Layer 3 connectivity is required for ICCP.

Topology

The topology used in this example consists of two switches hosting an MC-LAG. The two switches are connected to an EX4600 switch and an MX80 router. Figure 2 shows the topology of this example.

Figure 2: Topology Diagram
Topology Diagram

Table 2 details the topology used in this configuration example.

Table 2: Components of the Topology for Configuring a Multichassis LAG Between Two Switches

HostnameBase HardwareMultichassis Link Aggregation Group

EX9200-A

EX9200-B

EX9200

EX9200

ae0 is configured as an aggregated Ethernet interface, and is used as an ICCP link. The following interfaces are part of ae0: et-1/0/0 and et-1/0/1 on EX9200-A and

et-1/0/0 and et-1/0/1 on EX9200-B.

ae1 is configured as an aggregated Ethernet interface and is used as an ICL link, and the following two interfaces are part of ae1:

xe-2/0/3 and xe-2/0/4 on EX9200-A and

xe-2/0/3 and xe-2/0/4 on EX9200-B.

ae2 is configured as an MC-LAG, and the following interfaces are part of ae2:

et-1/2/0 on EX9200-A and et-1/2/0 on EX9200-B.

ae4 is configured as an MC-LAG, and the following interfaces are part of ae4:

xe-2/0/0 on EX9200-A and xe-2/0/0 on EX9200-B.

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them in a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

EX9200-A

set chassis aggregated-devices ethernet device-count 20
set interfaces et-1/0/0 ether-options 802.3ad ae0
set interfaces et-1/0/1 ether-options 802.3ad ae0
set interfaces xe-2/0/3 hold-time up 100
set interfaces xe-2/0/3 hold-time down 9000
set interfaces xe-2/0/3 ether-options 802.3ad ae1
set interfaces xe-2/0/4 hold-time up 100
set interfaces xe-2/0/4 hold-time down 9000
set interfaces xe-2/0/4 ether-options 802.3ad ae1
set interfaces et-1/2/0 ether-options 802.3ad ae2
set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 aggregated-ether-options lacp periodic fast
set interfaces ae0 unit 0 family inet address 192.168.90.1/24
set interfaces ae1 description ICL-LINK
set interfaces ae1 aggregated-ether-options lacp active
set interfaces ae1 aggregated-ether-options lacp periodic fast
set interfaces ae1 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae1 unit 0 family ethernet-switching vlan members all
set interfaces ae2 aggregated-ether-options lacp active
set interfaces ae2 aggregated-ether-options lacp periodic fast
set interfaces ae2 aggregated-ether-options lacp system-id 00:01:02:03:04:05
set interfaces ae2 aggregated-ether-options lacp admin-key 3
set interfaces ae2 aggregated-ether-options mc-ae mc-ae-id 3
set interfaces ae2 aggregated-ether-options mc-ae redundancy-group 1
set interfaces ae2 aggregated-ether-options mc-ae chassis-id 0
set interfaces ae2 aggregated-ether-options mc-ae mode active-active
set interfaces ae2 aggregated-ether-options mc-ae status-control active
set interfaces ae2 aggregated-ether-options mc-ae init-delay-time 520
set interfaces ae2 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
set interfaces ae2 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae2 unit 0 family ethernet-switching vlan members all
set interfaces irb unit 100 family inet address 192.168.10.3/24 arp 192.168.10.2 l2-interface ae1.0
set interfaces irb unit 100 family inet address 192.168.10.3/24 arp 192.168.10.2 mac 3c:8a:b0:85:78:70
set interfaces irb unit 100 family inet address 192.168.10.3/24 vrrp-group 1 virtual-address 192.168.10.1
set interfaces irb unit 100 family inet address 192.168.10.3/24 vrrp-group 1 priority 150
set interfaces irb unit 100 family inet address 192.168.10.3/24 vrrp-group 1 accept-data
set interfaces lo0 unit 0 family inet address 192.18.39.1/32
set protocols iccp local-ip-addr 192.18.39.1
set protocols iccp peer 192.18.39.2 session-establishment-hold-time 50
set protocols iccp peer 192.18.39.2 redundancy-group-id-list 1
set protocols iccp peer 192.18.39.2 backup-liveness-detection backup-peer-ip 10.105.5.6
set protocols iccp peer 192.18.39.2 liveness-detection minimum-interval 2000
set protocols iccp peer 192.18.39.2 liveness-detection multiplier 4
set multi-chassis multi-chassis-protection 192.18.39.2 interface ae1
set switch-options service-id 1
set vlans rack_1 vlan-id 100
set vlans rack_1 l3-interface irb.100
set forwarding-options dhcp-relay forward-snooped-clients all-interfaces
set forwarding-options dhcp-relay overrides allow-snooped-clients
set forwarding-options dhcp-relay server-group GVP-DHCP 10.105.5.202
set forwarding-options dhcp-relay active-server-group GVP-DHCP
set forwarding-options dhcp-relay route-suppression destination
set forwarding-options dhcp-relay group Floor1 interface irb.100
set forwarding-options dhcp-relay relay-option-82 circuit-id use-interface-description device
set protocols rstp interface ae2
set protocols rstp interface ae4
set protocols rstp system-identifier 00:01:02:03:04:05
set protocols rstp bridge-priority 0
set interfaces xe-2/0/0 ether-options 802.3ad ae4
set interfaces ae4 aggregated-ether-options lacp active
set interfaces ae4 aggregated-ether-options lacp periodic fast
set interfaces ae4 aggregated-ether-options lacp system-id 00:01:02:03:04:06
set interfaces ae4 aggregated-ether-options lacp admin-key 7
set interfaces ae4 aggregated-ether-options mc-ae mc-ae-id 7
set interfaces ae4 aggregated-ether-options mc-ae redundancy-group 1
set interfaces ae4 aggregated-ether-options mc-ae chassis-id 1
set interfaces ae4 aggregated-ether-options mc-ae mode active-active
set interfaces ae4 aggregated-ether-options mc-ae status-control standby
set interfaces ae4 aggregated-ether-options mc-ae init-delay-time 520
set interfaces ae4 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
set interfaces ae4 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae4 unit 0 family ethernet-switching vlan members v51
set interfaces ae4 unit 0 family ethernet-switching vlan members v54
set vlans v54 vlan-id 54
set vlans v54 l3-interface irb.54
set interfaces irb unit 54 family inet address 192.168.54.2/24 arp 192.168.54.1 l2-interface ae1.0
set interfaces irb unit 54 family inet address 192.168.54.2/24 arp 192.168.54.1 mac 3c:8a:b0:85:78:70
set interfaces irb unit 54 family inet address 192.168.54.2/24 vrrp-group 4 virtual-address 192.168.54.3
set interfaces irb unit 54 family inet address 192.168.54.2/24 vrrp-group 4 priority 200
set protocols igmp-snooping vlan rack_1
set protocols igmp-snooping vlan v54
set multicast-snooping-options multichassis-lag-replicate-state
set protocols igmp-snooping vlan rack_1 interface ae1.0 multicast-router-interface
set protocols igmp-snooping vlan v54 interface ae1.0 multicast-router-interface
set protocols ospf area 0.0.0.0 interface lo0.0
set protocols ospf area 0.0.0.0 interface ae0.0
set protocols ospf area 0.0.0.0 interface irb.54
set protocols ospf area 0.0.0.0 interface irb.100
set protocols pim interface irb.54
set protocols pim interface irb.100
set protocols pim interface lo0.0
set protocols pim rp bootstrap-priority 150
set protocols pim rp local address 192.18.39.1

EX9200-B

set chassis aggregated-devices ethernet device-count 20
set interfaces et-1/0/0 ether-options 802.3ad ae0
set interfaces et-1/0/1 ether-options 802.3ad ae0
set interfaces xe-2/0/3 hold-time up 100
set interfaces xe-2/0/3 hold-time down 9000
set interfaces xe-2/0/3 ether-options 802.3ad ae1
set interfaces xe-2/0/4 hold-time up 100
set interfaces xe-2/0/4 hold-time down 9000
set interfaces xe-2/0/4 ether-options 802.3ad ae1
set interfaces et-1/2/0 ether-options 802.3ad ae2
set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 aggregated-ether-options lacp periodic fast
set interfaces ae0 unit 0 family inet address 192.168.90.2/24
set interfaces ae1 description ICL-LINK
set interfaces ae1 aggregated-ether-options lacp active
set interfaces ae1 aggregated-ether-options lacp periodic fast
set interfaces ae1 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae1 unit 0 family ethernet-switching vlan members all
set interfaces ae2 aggregated-ether-options lacp active
set interfaces ae2 aggregated-ether-options lacp periodic fast
set interfaces ae2 aggregated-ether-options lacp system-id 00:01:02:03:04:05
set interfaces ae2 aggregated-ether-options lacp admin-key 3
set interfaces ae2 aggregated-ether-options mc-ae mc-ae-id 3
set interfaces ae2 aggregated-ether-options mc-ae redundancy-group 1
set interfaces ae2 aggregated-ether-options mc-ae chassis-id 1
set interfaces ae2 aggregated-ether-options mc-ae mode active-active
set interfaces ae2 aggregated-ether-options mc-ae init-delay-time 520
set interfaces ae2 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
set interfaces ae2 aggregated-ether-options mc-ae status-control standby
set interfaces ae2 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae2 unit 0 family ethernet-switching vlan members all
set interfaces irb unit 100 family inet address 192.168.10.2/24 arp 192.168.10.3 l2-interface ae1.0
set interfaces irb unit 100 family inet address 192.168.10.2/24 arp 192.168.10.3 mac 00:1f:12:b6:6f:f0
set interfaces irb unit 100 family inet address 192.168.10.2/24 vrrp-group 1 virtual-address 192.168.10.1
set interfaces irb unit 100 family inet address 192.168.10.2/24 vrrp-group 1 priority 200
set interfaces irb unit 100 family inet address 192.168.10.2/24 vrrp-group 1 accept-data
set interfaces lo0 unit 0 family inet address 192.18.39.2/32
set protocols iccp local-ip-addr 192.18.39.2
set protocols iccp peer 192.18.39.1 session-establishment-hold-time 50
set protocols iccp peer 192.18.39.1 redundancy-group-id-list 1
set protocols iccp peer 192.18.39.1 backup-liveness-detection backup-peer-ip 10.105.5.5
set protocols iccp peer 192.18.39.1 liveness-detection minimum-interval 2000
set protocols iccp peer 192.18.39.1 liveness-detection multiplier 4
set multi-chassis multi-chassis-protection 192.18.39.1 interface ae1
set switch-options service-id 1
set vlans rack_1 vlan-id 100
set vlans rack_1 l3-interface irb.100
set forwarding-options dhcp-relay forward-snooped-clients all-interfaces
set dhcp-relay overrides allow-snooped-clients
set forwarding-options dhcp-relay server-group GVP-DHCP 10.105.5.202
set forwarding-options dhcp-relay active-server-group GVP-DHCP
set forwarding-options dhcp-relay route-suppression destination
set forwarding-options dhcp-relay group Floor1 interface irb.100
set forwarding-options dhcp-relay relay-option-82 circuit-id use-interface-description device
set protocols rstp interface ae2
set protocols rstp interface ae4
set protocols rstp system-identifier 00:01:02:03:04:05
set protocols rstp bridge-priority 0
set interfaces xe-2/0/0 ether-options 802.3ad ae4
set interfaces ae4 aggregated-ether-options lacp active
set interfaces ae4 aggregated-ether-options lacp periodic fast
set interfaces ae4 aggregated-ether-options lacp system-id 00:01:02:03:04:06
set interfaces ae4 aggregated-ether-options lacp admin-key 7
set interfaces ae4 aggregated-ether-options mc-ae mc-ae-id 7
set interfaces ae4 aggregated-ether-options mc-ae redundancy-group 1
set interfaces ae4 aggregated-ether-options mc-ae chassis-id 0
set interfaces ae4 aggregated-ether-options mc-ae mode active-active
set interfaces ae4 aggregated-ether-options mc-ae status-control active
set interfaces ae4 aggregated-ether-options mc-ae init-delay-time 520
set interfaces ae4 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
set interfaces ae4 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae4 unit 0 family ethernet-switching vlan members v51
set interfaces ae4 unit 0 family ethernet-switching vlan members v54
set vlans v54 vlan-id 54
set vlans v54 l3-interface irb.54
set interfaces irb unit 54 family inet address 192.168.54.1/24 arp 192.168.54.2 l2-interface ae1.0
set interfaces irb unit 54 family inet address 192.168.54.1/24 arp 192.168.54.2 mac 00:1f:12:b6:6f:f0
set interfaces irb unit 54 family inet address 192.168.54.1/24 vrrp-group 4 virtual-address 192.168.54.3
set interfaces irb unit 54 family inet address 192.168.54.1/24 vrrp-group 4 priority 150
set protocols igmp-snooping vlan rack_1
set protocols igmp-snooping vlan v54
set multicast-snooping-options multichassis-lag-replicate-state
set protocols igmp-snooping vlan rack_1 interface ae1.0 multicast-router-interface
set protocols igmp-snooping vlan v54 interface ae1.0 multicast-router-interface
set protocols ospf area 0.0.0.0 interface lo0.0
set protocols ospf area 0.0.0.0 interface ae0.0
set protocols ospf area 0.0.0.0 interface irb.54
set protocols ospf area 0.0.0.0 interface irb.100
set protocols pim interface lo0.0
set protocols pim rp bootstrap-priority 200
set protocols pim rp local address 192.18.39.2

Configuring MC-LAG on Switch A

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy.

  1. Configure the number of aggregated Ethernet interfaces to be created on Switch A.
    [edit chassis]

    user@switch# set aggregated-devices ethernet device-count 20
  2. Add member interfaces to the aggregated Ethernet interfaces that will be used for the Inter-Chassis Control Protocol (ICCP) interface.
    [edit interfaces]

    user@switch# set et-1/0/0 ether-options 802.3ad ae0
    user@switch# set et-1/0/1 ether-options 802.3ad ae0
  3. Configure the member interfaces for the interchassis link (ICL) with a hold-time value that is higher than the configured BFD timer to prevent the ICL from being advertised as being down before the ICCP link is down.

    If the ICL goes down before the ICCP link goes down, the MC-LAG interface configured as the standby status-control peer goes up and down. The interface going up and down causes a delay in convergence.

    [edit interfaces]

    user@switch# set xe-2/0/3 hold-time up 100
    user@switch# set xe-2/0/3 hold-time down 9000
    user@switch# set xe-2/0/3 ether-options 802.3ad ae1
    user@switch# set xe-2/0/4 hold-time up 100
    user@switch# set xe-2/0/4 hold-time down 9000
    user@switch# set xe-2/0/4 ether-options 802.3ad ae1
  4. Specify the member interfaces that belong to interface ae2.
    [edit interfaces]

    user@switch# set et-1/2/0 ether-options 802.3ad ae2
  5. Configure ae0 as a Layer 3 interface.
    [edit interfaces]

    user@switch# set ae0 aggregated-ether-options lacp active
    user@switch# set ae0 aggregated-ether-options lacp periodic fast
    user@switch# set ae0 unit 0 family inet address 192.168.90.1/24
  6. Configure ae1 as a Layer 2 interface.
    [edit interfaces]

    user@switch# set ae1 description ICL-LINK
    user@switch# set ae1 aggregated-ether-options lacp active
    user@switch# set ae1 aggregated-ether-options lacp periodic fast
  7. Configure a trunk interface between EX9200-A and EX9200-B.
    [edit interfaces]

    user@switch# set ae1 unit 0 family ethernet-switching interface-mode trunk
    user@switch# set ae1 unit 0 family ethernet-switching vlan members all
  8. Configure the LACP parameters on ae2.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options lacp active
    user@switch# set ae2 aggregated-ether-options lacp periodic fast
  9. Configure the LACP administration key on ae2.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options lacp system-id 00:01:02:03:04:06
  10. Configure the MC-AE interface properties.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options lacp admin-key 3
    user@switch# set ae2 aggregated-ether-options mc-ae mc-ae-id 3
    user@switch# set ae2 aggregated-ether-options mc-ae redundancy-group 1
  11. Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae chassis-id 0
  12. Specify the mode of the MC-LAG that the aggregated Ethernet interface belongs to.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae mode active-active
  13. Configure the status control on the switch that hosts the MC-LAG.

    If one switch is in active mode, then the other switch must be in standby mode.

    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae status-control active
  14. Specify the time in seconds by when routing adjacencies must form.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae init-delay-time 520
  15. Specify that if a peer of the MC-LAG group goes down, the peer that is configured as status-control active becomes the active peer.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
  16. Configure ae2 as a trunk port with membership in all VLANs.
    [edit interfaces]

    user@switch# set ae2 unit 0 family ethernet-switching interface-mode trunk
    user@switch# set ae2 unit 0 family ethernet-switching vlan members all
  17. Configure an integrated routing and bridging (IRB) interface on VLAN 100.

    To configure an MC-LAG IRB, configure static Address Resolution Protocol (ARP) on the MC-LAG IRB peers to allow routing protocols to traverse the IRB interface.

    [edit interfaces]

    user@switch# set irb unit 100 family inet address 192.168.10.3/24 arp 192.168.10.2 l2-interface ae1.0
    user@switch# set irb unit 100 family inet address 192.168.10.3/24 arp 192.168.10.2 mac 3c:8a:b0:85:78:70
  18. Enable VRRP on the MC-LAGs by creating an IRB interface for each MC-LAG, assign a virtual IP address that is shared between each switch in the VRRP group, and assign an individual IP address for each individual member in the VRRP group.
    [edit interfaces]

    user@switch# set irb unit 100 family inet address 192.168.10.3/24 vrrp-group 1 virtual-address 192.168.10.1
    user@switch# set irb unit 100 family inet address 192.168.10.3/24 vrrp-group 1 priority 150
    user@switch# set irb unit 100 family inet address 192.168.10.3/24 vrrp-group 1 accept-data
  19. Configure a loopback interface.
    [edit interfaces]

    user@switch# set lo0 unit 0 family inet address 192.18.39.1/32
  20. Configure ICCP using the loopback address.
    [edit protocols]

    user@switch# set iccp local-ip-addr 192.18.39.1
  21. Configure the session establishment hold time for ICCP to connect faster.Note

    We recommend 50 seconds as the session establishment hold time value.

    [edit protocols]

    user@switch# set iccp peer 192.18.39.2 session-establishment-hold-time 50
    user@switch# set iccp peer 192.18.39.2 redundancy-group-id-list 1
    user@switch# set iccp peer 192.18.39.2 backup-liveness-detection backup-peer-ip 10.105.5.6
  22. To enable Bidirectional Forwarding Detection (BFD), configure the minimum receive interval.

    We recommend a minimum receive interval value of 6 seconds.

    [edit protocols]

    user@switch# set iccp peer 192.18.39.2 liveness-detection minimum-interval 2000
    user@switch# set iccp peer 192.18.39.2 liveness-detection multiplier 4


    [edit multi-chassis]

    user@switch# set multi-chassis-protection 192.18.39.2 interface ae1
  23. Specify the switch service ID.

    The switch service ID is used to synchronize applications, IGMP, ARP, and MAC learning across MC-LAG members.

    [edit switch-options]

    user@switch# set service-id 1
  24. Configure VLAN 100.
    [edit vlans]

    user@switch# set rack_1 vlan-id 100
    user@switch# set rack_1 l3-interface irb.100
  25. Configure forward snooped unicast packets on all interfaces.
    [edit fowarding-options]

    user@switch# set dhcp-relay forward-snooped-clients all-interfaces
  26. Create a binding entry to snoop unicast clients.
    [edit forwarding-options]

    user@switch# set dhcp-relay overrides allow-snooped-clients
  27. Create a DHCP server group.
    [edit forwarding-options]

    user@switch# set dhcp-relay server-group GVP-DHCP 10.105.5.202
  28. Apply a DHCP relay agent configuration to the named group of DHCP server addresses.
    [edit forwarding-options]

    user@switch# set dhcp-relay active-server-group GVP-DHCP
  29. Configure the relay agent to suppress the installation of ARP and route entries for corresponding client binding.
    [edit forwarding-options]

    user@switch# set dhcp-relay route-suppression destination
  30. Create a DHCP relay group that includes at least one interface.

    DHCP runs on the interfaces defined in the DHCP groups.

    [edit forwarding-options]

    user@switch# set dhcp-relay group Floor1 interface irb.100
  31. Configure DHCP relay with option 82.
    [edit forwarding-options]

    user@switch# set dhcp-relay relay-option-82 circuit-id use-interface-description device
  32. Enable the Rapid Spanning Tree Protocol on the ae2 and ae4 interfaces for optional loop prevention.
    [edit protocols]

    user@switch# set rstp interface ae2
    user@switch# set rstp interface ae4
  33. Configure the system identifier.
    [edit protocols]

    user@switch# set rstp system-identifier 00:01:02:03:04:05
  34. Set Rapid Spanning Tree Protocol priority to 0. This will make the MC-AE node the highest priority.
    [edit protocols]

    user@switch# set rstp bridge-priority 0
  35. Configure multicast with multichassis link aggregation between EX9200-A and an MX Series router.

    Specify the members that belong to ae4.

    [edit interfaces]

    user@switch# set xe-2/0/0 ether-options 802.3ad ae4
  36. Configure the LACP parameters on ae4.
    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options lacp active
    user@switch# set ae4 aggregated-ether-options lacp periodic fast
  37. Specify the LACP administration key.
    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options lacp system-id 00:01:02:03:04:06
    user@switch# set ae4 aggregated-ether-options lacp admin-key 7
    user@switch# set ae4 aggregated-ether-options mc-ae mc-ae-id 7
    user@switch# set ae4 aggregated-ether-options mc-ae redundancy-group 1
  38. Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to.
    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options mc-ae chassis-id 1
    user@switch# set ae4 aggregated-ether-options mc-ae mode active-active
  39. Configure the status control on the switch that hosts the MC-LAG.

    If one switch is in active mode, then the other switch must be in standby mode.

    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options mc-ae status-control standby
    user@switch# set ae4 aggregated-ether-options mc-ae init-delay-time 520
    user@switch# set ae4 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
  40. Configure ae4 as a Layer 2 interface.
    [edit interfaces]

    user@switch# set ae4 unit 0 family ethernet-switching interface-mode trunk
    user@switch# set ae4 unit 0 family ethernet-switching vlan members v51
    user@switch# set ae4 unit 0 family ethernet-switching vlan members v54
  41. Configure VLAN 54.
    [edit vlans]

    user@switch# set v54 vlan-id 54
    user@switch# set v54 l3-interface irb.54
  42. Configure an IRB interface on VLAN 100.

    You must configure static ARP on the MC-LAG peers to allow routing protocols to traverse over the IRB interface.

    [edit interfaces]

    user@switch# set irb unit 54 family inet address 192.168.54.2/24 arp 192.168.54.1 l2-interface ae1.0
    user@switch# set irb unit 54 family inet address 192.168.54.2/24 arp 192.168.54.1 mac 3c:8a:b0:85:78:70
  43. Enable VRRP on the MC-LAGs by creating an IRB interface for each MC-LAG, assign a virtual IP address that is shared between each switch in the VRRP group, and assign an individual IP address for each individual member in the VRRP group.
    [edit interfaces]

    user@switch# set irb unit 54 family inet address 192.168.54.2/24 vrrp-group 4 virtual-address 192.168.54.3
    user@switch# set irb unit 54 family inet address 192.168.54.2/24 vrrp-group 4 priority 200
  44. Enable IGMP snooping for all VLANs.
    [edit protocols]

    user@switch# set igmp-snooping vlan rack_1
    user@switch# set igmp-snooping vlan v54
  45. Synchronize multicast states across MC-LAG peers when bridge domains are configured.

    At the global level, IGMP join and leave messages are replicated from the MC-LAG interface active link to the standby link to enable faster recovery of membership information after a failover.

    [edit multicast-snooping-options]

    user@switch# set multichassis-lag-replicate-state
  46. Configure the ICL-PL interface as a router-facing interface.
    [edit protocols]

    user@switch# set igmp-snooping vlan rack_1 interface ae1.0 multicast-router-interface
    user@switch# set igmp-snooping vlan v54 interface ae1.0 multicast-router-interface
  47. Configure an OSPF area.
    [edit protocols]

    user@switch# set ospf area 0.0.0.0 interface lo0.0
    user@switch# set ospf area 0.0.0.0 interface ae0.0
    user@switch# set ospf area 0.0.0.0 interface irb.54
    user@switch# set ospf area 0.0.0.0 interface irb.100
  48. Configure Protocol Independent Multicast (PIM) as the multicast protocol.
    [edit protocols]

    user@switch# set pim interface irb.54
    user@switch# set pim interface irb.100
  49. Configure the loopback interface.
    [edit protocols]

    user@switch# set pim interface lo0.0
  50. Configure the switch as a secondary rendezvous point (RP).

    A lower priority setting indicates that the secondary RP is in a bootstrap configuration.

    [edit protocols]

    user@switch# set pim rp bootstrap-priority 150
    user@switch# set pim rp local address 192.18.39.1
  51. (Optional) To change the MC-AE mode, use this command.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae mode active-standby

Configuring MC-LAG on Switch B

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy.

  1. Configure the number of aggregated Ethernet interfaces to be created on Switch B.
    [edit chassis]

    user@switch# set aggregated-devices ethernet device-count 20
  2. Add member interfaces to the aggregated Ethernet interfaces that will be used for the Inter-Chassis Control Protocol (ICCP) interface.
    [edit interfaces]

    user@switch# set et-1/0/0 ether-options 802.3ad ae0
    user@switch# set et-1/0/1 ether-options 802.3ad ae0
  3. Configure the member interfaces for the interchassis link (ICL) with a hold-time value that is higher than the configured BFD timer to prevent the ICL from being advertised as being down before the ICCP link is down.

    If the ICL goes down before the ICCP link goes down, the MC-LAG interface configured as the standby status-control peer goes up and down. The interface going up and down causes a delay in convergence.

    [edit interfaces]

    user@switch# set xe-2/0/3 hold-time up 100
    user@switch# set xe-2/0/3 hold-time down 9000
    user@switch# set xe-2/0/3 ether-options 802.3ad ae1
    user@switch# set xe-2/0/4 hold-time up 100
    user@switch# set xe-2/0/4 hold-time down 9000
    user@switch# set xe-2/0/4 ether-options 802.3ad ae1
  4. Specify the member interfaces that belong to interface ae2.
    [edit interfaces]

    user@switch# set et-1/2/0 ether-options 802.3ad ae2
  5. Configure ae0 as a Layer 3 interface.
    [edit interfaces]

    user@switch# set ae0 aggregated-ether-options lacp active
    user@switch# set ae0 aggregated-ether-options lacp periodic fast
    user@switch# set ae0 unit 0 family inet address 192.168.90.2/24
  6. Configure ae1 as a Layer 2 interface.
    [edit interfaces]

    user@switch# set ae1 description ICL-LINK
    user@switch# set ae1 aggregated-ether-options lacp active
    user@switch# set ae1 aggregated-ether-options lacp periodic fast
  7. Configure a trunk interface between EX9200-A and EX9200-B.
    [edit interfaces]

    user@switch# set ae1 unit 0 family ethernet-switching interface-mode trunk
    user@switch# set ae1 unit 0 family ethernet-switching vlan members all
  8. Configure the LACP parameters on ae2.
    [edit interfaces]

    user@switch# set interfaces ae2 aggregated-ether-options lacp active
    user@switch# set interfaces ae2 aggregated-ether-options lacp periodic fast
  9. Configure the LACP administration key on ae2.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options lacp system-id 00:01:02:03:04:05
  10. Configure the MC-AE interface properties.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options lacp admin-key 3
    user@switch# set ae2 aggregated-ether-options mc-ae mc-ae-id 3
    user@switch# set ae2 aggregated-ether-options mc-ae redundancy-group 1
  11. Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae chassis-id 1
  12. Specify the mode of the MC-LAG that the aggregated Ethernet interface belongs to.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae mode active-active
  13. Specify time in seconds by when routing adjacencies must form.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae init-delay-time 520
  14. Specify that if a peer of the MC-LAG group goes down, the peer that is configured as status-control active becomes the active peer.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
  15. Configure the status control on the switch that hosts the MC-LAG.

    If one switch is in standby mode, then the other switch must be in active mode.

    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae status-control standby
  16. Configure ae2 as a trunk port with membership in all VLANs.
    [edit interfaces]

    user@switch# set ae2 unit 0 family ethernet-switching interface-mode trunk
    user@switch# set ae2 unit 0 family ethernet-switching vlan members all
  17. Configure an integrated routing and bridging (IRB) interface on VLAN 100.

    To configure an MC-LAG IRB, configure static Address Resolution Protocol (ARP) on the MC-LAG IRB peers to allow routing protocols to traverse the IRB interface.

    [edit interfaces]

    user@switch# set irb unit 100 family inet address 192.168.10.2/24 arp 192.168.10.3 l2-interface ae1.0
    user@switch# set irb unit 100 family inet address 192.168.10.2/24 arp 192.168.10.3 mac 00:1f:12:b6:6f:f0
  18. Enable VRRP on the MC-LAGs by creating an IRB interface for each MC-LAG, assign a virtual IP address that is shared between each switch in the VRRP group, and assign an individual IP address for each individual member in the VRRP group.
    [edit interfaces]

    user@switch# set irb unit 100 family inet address 192.168.10.2/24 vrrp-group 1 virtual-address 192.168.10.1
    user@switch# set irb unit 100 family inet address 192.168.10.2/24 vrrp-group 1 priority 200
    user@switch# set irb unit 100 family inet address 192.168.10.2/24 vrrp-group 1 accept-data
  19. Configure a loopback interface.
    [edit interfaces]

    user@switch# set lo0 unit 0 family inet address 192.18.39.2/32
  20. Configure ICCP using the loopback address.
    [edit protocols]

    user@switch# set iccp local-ip-addr 192.18.39.2
  21. Configure the session establishment hold time for ICCP to connect faster.Note

    We recommend 50 seconds as the session establishment hold time value.

    [edit protocols]

    user@switch# set iccp peer 192.18.39.1 session-establishment-hold-time 50
    user@switch# set iccp peer 192.18.39.1 redundancy-group-id-list 1
    user@switch# set iccp peer 192.18.39.1 backup-liveness-detection backup-peer-ip 10.105.5.5
  22. To enable Bidirectional Forwarding Detection (BFD), configure the minimum receive interval.

    We recommend a minimum receive interval value of 6 seconds.

    [edit protocols]

    user@switch# set iccp peer 192.18.39.1 liveness-detection minimum-interval 2000
    user@switch# set iccp peer 192.18.39.1 liveness-detection multiplier 4


    [edit multi-chassis]

    user@switch# set multi-chassis-protection 192.18.39.1 interface ae1
  23. Specify the switch service ID.

    The switch service ID is used to synchronize applications, IGMP, ARP, and MAC learning across MC-LAG members.

    [edit switch-options]

    user@switch# set service-id 1
  24. Configure VLAN 100.
    [edit vlans]

    user@switch# set rack_1 vlan-id 100
    user@switch# set rack_1 l3-interface irb.100
  25. Configure forward snooped unicast packets on all interfaces.
    [edit forwarding-options]

    user@switch# set dhcp-relay forward-snooped-clients all-interfaces
  26. Create a binding entry to snoop unicast clients.
    [edit forwarding-options]

    user@switch# set dhcp-relay overrides allow-snooped-clients
  27. Create a DHCP server group.
    [edit forwarding-options]

    user@switch# set dhcp-relay server-group GVP-DHCP 10.105.5.202
  28. Apply a DHCP relay agent configuration to the named group of DHCP server addresses.
    [edit forwarding-options]

    user@switch# set dhcp-relay active-server-group GVP-DHCP
  29. Configure the relay agent to suppress the installation of ARP and route entries for corresponding client binding.
    [edit forwarding-options]

    user@switch# set dhcp-relay route-suppression destination
  30. Create a DHCP relay group that includes at least one interface.

    DHCP runs on the interfaces defined in the DHCP groups.

    [edit forwarding-options]

    user@switch# set dhcp-relay group Floor1 interface irb.100
  31. Configure DHCP relay with option 82.
    [edit forwarding-options]

    user@switch# set dhcp-relay relay-option-82 circuit-id use-interface-description device
  32. Enable the Rapid Spanning Tree Protocol on the ae2 and ae4 interfaces for optional loop prevention.
    [edit protocols]

    user@switch# set rstp interface ae2
    user@switch# set rstp interface ae4
  33. Configure the system identifier.
    [edit protocols]

    user@switch# set rstp system-identifier 00:01:02:03:04:05
  34. Set Rapid Spanning Tree Protocol priority to 0. This will make the MC-AE node the highest priority.
    [edit protocols]

    user@switch# set rstp bridge-priority 0
  35. Configure multicast with multichassis link aggregation between EX9200-B and an MX Series router.

    Specify the members that belong to ae4.

    [edit interfaces]

    user@switch# set xe-2/0/0 ether-options 802.3ad ae4
  36. Configure the LACP parameters on ae4.
    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options lacp active
    user@switch# set ae4 aggregated-ether-options lacp periodic fast
  37. Specify the LACP administration key.
    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options lacp system-id 00:01:02:03:04:06
    user@switch# set ae4 aggregated-ether-options lacp admin-key 7
    user@switch# set ae4 aggregated-ether-options mc-ae mc-ae-id 7
    user@switch# set ae4 aggregated-ether-options mc-ae redundancy-group 1
  38. Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to on each switch.
    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options mc-ae chassis-id 0
    user@switch# set ae4 aggregated-ether-options mc-ae mode active-active
  39. Configure the status control on the switch that hosts the MC-LAG.

    If one switch is in standby mode, then the other switch must be in active mode.

    [edit interfaces]

    user@switch# set ae4 aggregated-ether-options mc-ae status-control active
    user@switch# set ae4 aggregated-ether-options mc-ae init-delay-time 520
    user@switch# set ae4 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
  40. Configure ae4 as a Layer 2 interface.
    [edit interfaces]

    user@switch# set ae4 unit 0 family ethernet-switching interface-mode trunk
    user@switch# set ae4 unit 0 family ethernet-switching vlan members v51
    user@switch# set ae4 unit 0 family ethernet-switching vlan members v54
  41. Configure VLAN 54.
    [edit vlans]

    user@switch# set v54 vlan-id 54
    user@switch# set v54 l3-interface irb.54
  42. Configure an IRB interface on VLAN 100.

    You must configure static ARP on the MC-LAG peers to allow routing protocols to traverse over the IRB interface.

    [edit interfaces]

    user@switch# set irb unit 54 family inet address 192.168.54.1/24 arp 192.168.54.2 l2-interface ae1.0
    user@switch# set irb unit 54 family inet address 192.168.54.1/24 arp 192.168.54.2 mac 00:1f:12:b6:6f:f0
  43. Enable VRRP on the MC-LAGs on each switch by creating an IRB interface for each MC-LAG, assign a virtual IP address that is shared between each switch in the VRRP group, and assign an individual IP address for each switch in the VRRP group.
    [edit interfaces]

    user@switch# set irb unit 54 family inet address 192.168.54.1/24 vrrp-group 4 virtual-address 192.168.54.3
    user@switch# set irb unit 54 family inet address 192.168.54.1/24 vrrp-group 4 priority 150
  44. Enable IGMP snooping for all VLANs.
    [edit protocols]

    user@switch# set igmp-snooping vlan rack_1
    user@switch# set igmp-snooping vlan v54
  45. Synchronize multicast states across MC-LAG peers when bridge domains are configured.

    At the global level, IGMP join and leave messages are replicated from the MC-LAG interface active link to the standby link to enable faster recovery of membership information after a failover.

    [edit multicast-snooping-options]

    user@switch# set multichassis-lag-replicate-state
  46. Configure the ICL-PL interface as a router-facing interface.
    [edit protocols]

    user@switch# set igmp-snooping vlan rack_1 interface ae1.0 multicast-router-interface
    user@switch# set igmp-snooping vlan v54 interface ae1.0 multicast-router-interface
  47. Configure an OSPF area.
    [edit protocols]

    user@switch# set ospf area 0.0.0.0 interface lo0.0
    user@switch# set ospf area 0.0.0.0 interface ae0.0
    user@switch# set ospf area 0.0.0.0 interface irb.54
    user@switch# set ospf area 0.0.0.0 interface irb.100
  48. Configure Protocol Independent Multicast (PIM) as the multicast protocol.
    [edit protocols]

    user@switch# set pim interface irb.54
    user@switch# set pim interface irb.100
  49. Configure the loopback interface.
    [edit protocols]

    user@switch# set pim interface lo0.0
  50. Configure the switch as a secondary rendezvous point (RP).

    A lower priority setting indicates that the secondary RP is in a bootstrap configuration.

    [edit protocols]

    user@switch# set pim rp bootstrap-priority 200
    user@switch# set pim rp local address 192.18.39.2
  51. (Optional) To change the MC-AE mode, use this command.
    [edit interfaces]

    user@switch# set ae2 aggregated-ether-options mc-ae mode active-standby

Verification

Confirm that the configuration is working properly.

Verifying ICCP on MC-LAG

Purpose

Verify that ICCP is running on each device in the MC-LAG.

Action

  1. Verify that ICCP is running on Switch A.
    root@EX92000-A> show iccp
  2. Verify that ICCP is running on Switch B.
    root@EX9200-B> show iccp

Meaning

This output shows that the TCP connection between the peers hosting the MC-LAG is up, liveness detection is up, and MCSNOOPD and ESWD client applications are running.

Verifying LACP on MC-LAG

Purpose

Verify that LACP is working properly on each device in the MC-LAG.

Action

  1. Verify that the LACP interfaces are up and running on Switch A.
    root@EX9200-A> show lacp interfaces
  2. Verify that the LACP interfaces are up and running on Switch B.
    root@EX9200-B> show lacp interfaces

Meaning

This output means that both devices and all related interfaces are properly participating in LACP negotiations.

Verifying Aggregated Ethernet Interfaces in MC-LAG

Purpose

Verify that all of the ae interfaces are configured properly in the MC–LAG.

Action

  1. Verify the ae interfaces on Switch A.
    user@EX9200-A> show interfaces mc-ae
  2. Verify the ae interfaces on Switch B.
    root@EX9200-B> show interface mc-ae

Meaning

This output means that the mc-ae interfaces on each device are up and active.

Verifying MAC Learning on MC-LAG

Purpose

Verify that MAC learning between devices is happening in the MC-LAG.

Action

  1. Show Ethernet switching table in Switch A.
    root@EX9200-A> show ethernet-switching table
  2. Show Ethernet switching table in Switch B.
    root@EX9200-B> show ethernet-switching table

Meaning

This output means that the MAC addresses are properly learned within the shared VLANs defined in the MC-LAG. This includes IRB interfaces to define the MC-LAG as well as the ICL interfaces used to configure VRRP.

Verifying VRRP in MC-LAG

Purpose

Verify that VRRP is up and active between the devices in the MC-LAG.

Action

  1. Confirm that VRRP is up and active on Switch A.
    root@EX9200-A> show vrrp

    In this example, Switch A is the backup VRRP member.

  2. Confirm that VRRP is up and active on Switch B.
    root@EX9200-B> show vrrp

    In this example, Switch B is the master VRRP member.

Meaning

This output means that VRRP is up and running properly.

Verifying OSPF on MC-LAG

Purpose

Verify that OSPF is properly up and running with MC-LAG.

Action

  1. Show OSPF neighbors on Switch A.
    root@EX9200-A> show ospf neighbor
  2. Show OSPF routing table on Switch A.
    root@EX9200-A> show ospf route
  3. Show OSPF neighbors on Switch B.
    root@EX9200-B> show ospf neighbor
  4. Show OSPF routing table on Switch B.
    root@EX9200-B> show ospf route

Requirements

This example uses the following hardware and software components:

  • Junos OS Release 16.1R1 for EX Series

  • Two EX9200 switches

Note

This configuration example has been tested using the software release listed and is assumed to work on all later releases.

Before you configure an MC-LAG, be sure that you understand how to:

Overview

In this example, you configure an MC-LAG across two switches, consisting of two aggregated Ethernet interfaces, multichassis protection using the ICL, ICCP for the peers hosting the MC-LAG, and Layer 3 connectivity between MC-LAG peers. Layer 3 connectivity is required for ICCP.

To simplify the MC-LAG configuration process, you will enable configuration synchronization and configuration consistency check. Configuration synchronization enables you to easily propagate, synchronize, and commit configurations from one MC-LAG peer to another. You can log into any one of the MC-LAG peers to manage both MC-LAG peers, thus having a single point of management. Configuration consistency check uses the Inter-Chassis Control Protocol (ICCP) to exchange MC-LAG configuration parameters (chassis ID, service ID, and so on) and checks for any configuration inconsistencies across MC-LAG peers. When there is an inconsistency, you are notified and can take action to resolve it. Configuration consistency check is invoked after you issue a commit on an MC-LAG peer.

On the EX9200-A switch, you will configure the following configuration synchronization and configuration consistency check parameters:

  • Local, remote, and global configuration groups that are synchronized to the EX9200-B switch.

  • Conditional groups.

  • Apply groups.

  • NETCONF over SSH.

  • MC-LAG peer details and user authentication details for MC-LAG configuration synchronization.

  • peers-synchronize statement to synchronize the configurations between local and remote MC-LAG peers by default.

  • set multi-chassis mc-lag consistency-check command for consistency check.

On the EX9200-B switch, the configuration process is much shorter and simpler. You will configure the following configuration synchronization and configuration consistency check parameters:

  • Apply groups.

  • NETCONF over SSH.

  • MC-LAG peer details and user authentication details for MC-LAG configuration synchronization.

  • peers-synchronize statement to synchronize and commit the configurations between local and remote MC-LAG peers.

  • multi-chassis mc-lag consistency-check statement to enable consistency check.

Topology

The topology used in this example consists of two switches hosting an MC-LAG. Figure 3 shows the topology of this example.

Figure 3: Topology Diagram
Topology Diagram

Table 3 details the topology used in this configuration example.

Table 3: Components of the Topology for Configuring a Multichassis LAG Between Two Switches

HostnameBase HardwareMultichassis Link Aggregation Group

EX9200-A

EX9200-B

EX9200

EX9200

ae0 is configured as an aggregated Ethernet interface, and is used as an ICCP link, and the following interfaces are part of ae0:

xe-0/3/6 and xe-1/3/6.

ae1 is configured as an aggregated Ethernet interface and is used as an ICL link, and the following interfaces are part of ae1:

xe-0/3/7 and xe-1/3/7.

ae2 is configured as an MC-LAG, and the following interfaces are part of ae2:

xe-0/0/1 on Switch B and xe-1/0/1 on Switch A.

ae3 is configured as an MC-LAG, and the following interface is part of ae3 on both Switch A and Switch B:

xe-0/0/2.

Virtual Chassis

Virtual Chassis

Not applicable. Virtual Chassis are shown only for illustration purposes.

The Virtual Chassis are connected to the two EX9200 switches through LAG interfaces. The Virtual Chassis configuration is not included in this example and is only shown to illustrate a sample topology.

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them in a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

EX9200-A

set system login user MCLAG_Admin uid 2000
set system login user MCLAG_Admin class super-user
set system login user MCLAG_Admin authentication encrypted-password "$ABC123"
set system static-host-mapping EX9200-A inet 10.92.76.2
set system static-host-mapping EX9200-B inet 10.92.76.4
set system services netconf ssh
set system commit peers-synchronize
set system commit peers EX9200-B user MCLAG_Admin
set system commit peers EX9200-B authentication "$ABC123"
set interfaces irb unit 100 family inet address 192.168.100.2/24 arp 192.168.100.3 l2-interface ae1
set interfaces irb unit 100 family inet address 192.168.100.2/24 arp 192.168.100.3 mac 28:8a:1c:e5:3b:f0
set interfaces irb unit 100 family inet address 192.168.100.2/24 vrrp-group 1 virtual-address 192.168.100.1
set interfaces irb unit 100 family inet address 192.168.100.2/24 vrrp-group 1 priority 150
set interfaces irb unit 100 family inet address 192.168.100.2/24 vrrp-group 1 accept-data
set interfaces lo0 unit 0 family inet address 172.16.32.5/32
set routing-options static route 0.0.0.0/0 next-hop 10.92.77.254
set protocols ospf area 0.0.0.0 interface lo0.0 passive
set protocols ospf area 0.0.0.0 interface ae0.0
set protocols lldp interface all
set chassis aggregated-devices ethernet device-count 20
set groups MC_Config_Global
set groups MC_Config_Global when peers EX9200-A
set groups MC_Config_Global when peers EX9200-B
set groups MC_Config_Global interfaces xe-0/3/6 ether-options 802.3ad ae0
set groups MC_Config_Global interfaces xe-1/3/6 ether-options 802.3ad ae0
set groups MC_Config_Global interfaces ae0 description "ICCP Layer 3 Link with 2 members,xe-0/3/6,xe-1/3/6"
set groups MC_Config_Global interfaces ae0 aggregated-ether-options lacp active
set groups MC_Config_Global interfaces ae0 aggregated-ether-options lacp periodic fast
set groups MC_Config_Global interfaces ae0 aggregated-ether-options lacp system-id 00:01:02:03:04:05
set groups MC_Config_Global interfaces ae0 aggregated-ether-options lacp admin-key 0
set groups MC_Config_Global interfaces xe-0/3/7 ether-options 802.3ad ae1
set groups MC_Config_Global interfaces xe-1/3/7 ether-options 802.3ad ae1
set groups MC_Config_Global interfaces ae1 description "ICL Layer 2 link with 2 members,xe-0/3/7,1/3/7"
set groups MC_Config_Global interfaces ae1 unit 0 family ethernet-switching interface-mode trunk
set groups MC_Config_Global interfaces ae1 unit 0 family ethernet-switching vlan members all
set groups MC_Config_Global interfaces ae1 vlan-tagging
set groups MC_Config_Global interfaces ae1 aggregated-ether-options lacp active
set groups MC_Config_Global interfaces ae1 aggregated-ether-options lacp periodic fast
set groups MC_Config_Global interfaces ae1 aggregated-ether-options lacp system-id 00:01:02:03:04:06
set groups MC_Config_Global interfaces ae1 aggregated-ether-options lacp admin-key 1
set groups MC_Config_Global interfaces xe-0/0/1 ether-options 802.3ad ae2
set groups MC_Config_Global interfaces xe-1/0/1 ether-options 802.3ad ae2
set groups MC_Config_Global interfaces ae2 unit 0 description “MC-LAG interface with members xe-0/0/1,xe-1/0/1”
set groups MC_Config_Global interfaces ae2 unit 0 family ethernet-switching interface-mode trunk
set groups MC_Config_Global interfaces ae2 unit 0 family ethernet-switching vlan members all
set groups MC_Config_Global interfaces ae2 aggregated-ether-options lacp active
set groups MC_Config_Global interfaces ae2 aggregated-ether-options lacp periodic fast
set groups MC_Config_Global interfaces ae2 aggregated-ether-options lacp system-id 00:01:02:03:04:07
set groups MC_Config_Global interfaces ae2 aggregated-ether-options lacp admin-key 2
set groups MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae mc-ae-id 2
set groups MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae redundancy-group 1
set groups MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae mode active-active
set groups MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae init-delay-time 520
set groups MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
set groups MC_Config_Global interfaces xe-0/0/2 ether-options 802.3ad ae3
set groups MC_Config_Global interfaces ae3 unit 0 description “MC-LAG interface with members xe-0/0/2 on both switches”
set groups MC_Config_Global interfaces ae3 unit 0 family ethernet-switching interface-mode trunk
set groups MC_Config_Global interfaces ae3 unit 0 family ethernet-switching vlan members all
set groups MC_Config_Global interfaces ae3 aggregated-ether-options lacp active
set groups MC_Config_Global interfaces ae3 aggregated-ether-options lacp periodic fast
set groups MC_Config_Global interfaces ae3 aggregated-ether-options lacp system-id 00:01:02:03:04:08
set groups MC_Config_Global interfaces ae3 aggregated-ether-options lacp admin-key 3
set groups MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae mc-ae-id 3
set groups MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae redundancy-group 1
set groups MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae mode active-active
set groups MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae init-delay-time 520
set groups MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
set groups MC_Config_Global vlans v100 vlan-id 100
set groups MC_Config_Global vlans v100 l3-interface irb.100
set groups MC_Config_Global multi-chassis mc-lag consistency-check
set groups MC_Config_Global protocols rstp interface ae2
set groups MC_Config_Global protocols rstp interface ae3
set groups MC_Config_Global protocols rstp bridge-priority 0
set groups MC_Config_Global protocols rstp system-id 00:01:02:03:04:09
set groups MC_Config_Global switch-options service-id 1
set groups MC_Config_Local
set groups MC_Config_Local interfaces ae0 unit 0 family inet address 172.16.32.9/30
set groups MC_Config_Local interfaces ae2 aggregated-ether-options mc-ae chassis-id 0
set groups MC_Config_Local interfaces ae2 aggregated-ether-options mc-ae status-control active
set groups MC_Config_Local interfaces ae3 aggregated-ether-options mc-ae chassis-id 0
set groups MC_Config_Local interfaces ae3 aggregated-ether-options mc-ae status-control active
set groups MC_Config_Remote
set groups MC_Config_Remote interfaces ae0 unit 0 family inet address 172.16.32.10/30
set groups MC_Config_Remote interfaces ae2 aggregated-ether-options mc-ae chassis-id 1
set groups MC_Config_Remote interfaces ae2 aggregated-ether-options mc-ae status-control standby
set groups MC_Config_Remote interfaces ae3 aggregated-ether-options mc-ae chassis-id 1
set groups MC_Config_Remote interfaces ae3 aggregated-ether-options mc-ae status-control standby
set interfaces ae2 unit 0 multi-chassis-protection 172.16.32.6 interface ae1
set interfaces ae3 unit 0 multi-chassis-protection 172.16.32.6 interface ae1
set protocols iccp local-ip-addr 172.16.32.5
set protocols iccp peer 172.16.32.6 session-establishment-hold-time 50
set protocols iccp peer 172.16.32.6 redundancy-group-id-list 1
set protocols iccp peer 172.16.32.6 backup-liveness-detection backup-peer-ip 10.92.76.4
set protocols iccp peer 172.16.32.6 liveness-detection minimum-interval 2000
set protocols iccp peer 172.16.32.6 liveness-detection multiplier 4
set multi-chassis multi-chassis-protection 172.16.32.6 interface ae1
set apply-groups [ MC_Config_Global MC_Config_Local MC_Config_Remote ]

EX9200-B

set system login user MCLAG_Admin uid 2000
set system login user MCLAG_Admin class super-user
set system login user MCLAG_Admin authentication encrypted-password "$ABC123"
set system static-host-mapping EX9200-A inet 10.92.76.2
set system static-host-mapping EX9200-B inet 10.92.76.4
set system services netconf ssh
set system commit peers-synchronize
set system commit peers EX9200-A user MCLAG_Admin
set system commit peers EX9200-A authentication "$ABC123"
set interfaces irb unit 100 family inet address 192.168.100.3/24 arp 192.168.100.2 l2-interface ae1
set interfaces irb unit 100 family inet address 192.168.100.3/24 arp 192.168.100.2 mac 28:8a:1c:e3:f7:f0
set interfaces irb unit 100 family inet address 192.168.100.3/24 vrrp-group 1 virtual-address 192.168.100.1
set interfaces irb unit 100 family inet address 192.168.100.3/24 vrrp-group 1 priority 100
set interfaces irb unit 100 family inet address 192.168.100.3/24 vrrp-group 1 accept-data
set interfaces lo0 unit 0 family inet address 172.16.32.6/32
set routing-options static route 0.0.0.0/0 next-hop 10.92.77.254
set protocols ospf area 0.0.0.0 interface lo0 passive
set protocols ospf area 0.0.0.0 interface ae0
set protocols lldp interface all
set chassis aggregated-devices ethernet device-count 20
set interfaces ae2 unit 0 multi-chassis-protection 172.16.32.5 interface ae1
set interfaces ae3 unit 0 multi-chassis-protection 172.16.32.5 interface ae1
set protocols iccp local-ip-addr 172.16.32.6
set protocols iccp peer 172.16.32.5 session-establishment-hold-time 50
set protocols iccp peer 172.16.32.5 redundancy-group-id-list 1
set protocols iccp peer 172.16.32.5 backup-liveness-detection backup-peer-ip 10.92.76.2
set protocols iccp peer 172.16.32.5 liveness-detection minimum-interval 2000
set protocols iccp peer 172.16.32.5 liveness-detection multiplier 4
set apply-groups [ MC_Config_Global MC_Config_Local MC_Config_Remote ]

Configuring MC-LAG on EX9200-A

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy.

  1. Create a user account to access the switch, along with a user identifier (UID), a login class, and a password.
    [edit system]

    user@EX9200-A# set login user MCLAG_Admin uid 2000
    user@EX9200-A# set login user MCLAG_Admin class super-user
    user@EX9200-A# set login user MCLAG_Admin authentication encrypted-password “$ABC123”
  2. Statically map EX9200-A to 10.92.76.2 and EX9200-B to 10.92.76.4.
    [edit system]

    user@EX9200-A# set static-host-mapping EX9200-A inet 10.92.76.2
    user@EX9200-A# set static-host-mapping EX9200-B inet 10.92.76.4
  3. Enable NETCONF service using SSH.
    [edit system]

    user@EX9200-A# set services netconf ssh
  4. Enable the peers-synchronize statement to copy and load the MC-LAG configuration from EX9200-A to EX9200-B by default.
    [edit system]

    user@EX9200-A# set commit peers-synchronize
  5. Configure the hostname, usernames, and authentication details for EX9200-B, the peer with which EX9200-A will be synchronizing the MC-LAG configuration.
    [edit system]

    user@EX9200-A# set commit peers EX9200-B user MCLAG_Admin
    user@EX9200-A# set commit peers EX9200-B user authentication “$ABC123”
  6. Configure an MC-LAG IRB and configure static Address Resolution Protocol (ARP) on the MC-LAG IRB peers to allow routing protocols to traverse the IRB interface.
    [edit interfaces]

    user@EX9200-A# set irb unit 100 family inet address 192.168.100.2/24 arp 192.168.100.3 l2-interface ae1
    user@EX9200-A# set irb unit 100 family inet address 192.168.100.2/24 arp 192.168.100.3 mac 28:8a:1c:e5:3b:f0
  7. Enable VRRP on the MC-LAGs by assigning a virtual IP address that is shared between each switch in the VRRP group, and assigning an individual IP address for each individual member in the VRRP group.
    [edit interfaces]

    user@EX9200-A# set irb unit 100 family inet address 192.168.100.2/24 vrrp-group 1 virtual-address 192.168.100.1
    user@EX9200-A# set irb unit 100 family inet address 192.168.100.2/24 vrrp-group 1 priority 150
    user@EX9200-A# set irb unit 100 family inet address 192.168.100.2/24 vrrp-group 1 accept-data
  8. Configure a loopback interface.
    [edit interfaces]

    user@EX9200-A# set lo0 unit 0 family inet address 172.16.32.5/32
  9. Configure a default gateway.
    [edit routing-options]

    user@EX9200-A# set static route 0.0.0.0 next-hop 10.92.77.254
  10. Configure an OSPF area that includes the loopback interface and the ICCP interface.
    [edit protocols]

    user@EX9200-A# set ospf area 0.0.0.0 interface lo0 passive
    user@EX9200-A# set ospf area 0.0.0.0 interface ae0
  11. Configure Link Layer Discovery Protocol for all interfaces.
    [edit protocols]

    user@EX9200-A# set lldp interface all
  12. Configure the number of aggregated Ethernet interfaces to be created on EX9200-A.
    [edit chassis]

    user@EX9200-A# set aggregated-devices ethernet device-count 20
  13. Configure a configuration group for a global MC-LAG configuration that applies to both EX9200-A and EX9200-B.

    The global configuration is synchronized between EX9200-A and EX9200-B.

    [edit groups]

    user@EX9200-A# set MC_Config_Global
  14. Specify the peers that will apply the MC_Config_Global configuration group.
    [edit groups]

    user@EX9200-A# set MC_Config_Global when peers EX9200-A
    user@EX9200-A# set MC_Config_Global when peers EX9200-B
  15. Add member interfaces to the aggregated Ethernet interfaces that will be used for the Inter-Chassis Control Protocol (ICCP) interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces xe-0/3/6 ether-options 802.3ad ae0
    user@EX9200-A# set MC_Config_Global interfaces xe-1/3/6 ether-options 802.3ad ae0
  16. Configure the aggregated Ethernet interface (ae0) that will be used for the Inter-Chassis Control Protocol (ICCP) interface.Note

    You will be configuring the IP address for ae0 in a later step.

    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae0 description "ICCP Layer 3 Link with 2 members,xe-0/3/6,xe-1/3/6"
  17. Configure the LACP parameters on ae0.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae0 aggregated-ether-options lacp active
    user@EX9200-A# set MC_Config_Global interfaces ae0 aggregated-ether-options lacp periodic fast
  18. Configure the LACP system ID on ae0.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae0 aggregated-ether-options lacp system-id 00:01:02:03:04:05
  19. Configure the LACP administrative key on ae0.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae0 aggregated-ether-options lacp admin-key 0
  20. Add member interfaces to the aggregated Ethernet interface (ae1) that will be used for the ICL.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces xe-0/3/7 ether-options 802.3ad ae1
    user@EX9200-A# set MC_Config_Global interfaces xe-1/3/7 ether-options 802.3ad ae1
  21. Configure the aggregated Ethernet interface that will be used for the ICL.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae1 description "ICL Layer 2 link with 2 members,xe-0/3/7,1/3/7"
  22. Configure ae1 as a Layer 2 interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Global ae1 unit 0 family ethernet-switching interface-mode trunk
    user@EX9200-A# set MC_Config_Global ae1 unit 0 family ethernet-switching vlan members all
  23. Enable the reception and transmission of 802.1Q VLAN-tagged frames on ae1.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae1 vlan-tagging
  24. Configure the LACP parameters on ae1.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae1 aggregated-ether-options lacp active
    user@EX9200-A# set MC_Config_Global interfaces ae1 aggregated-ether-options lacp periodic fast
  25. Configure the LACP system ID on ae1.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae1 aggregated-ether-options lacp system-id 00:01:02:03:04:06
  26. Configure the LACP administrative key on ae1.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae1 aggregated-ether-options lacp admin-key 1
  27. Add member interfaces to the aggregated Ethernet interface (ae2) that will be used as the MC-LAG interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces xe-0/0/1 ether-options 802.3ad ae2
    user@EX9200-A# set MC_Config_Global interfaces xe-1/0/1 ether-options 802.3ad ae2
  28. Configure the aggregated Ethernet interface (ae2) that will be used as an MC-LAG interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 description “MC-LAG interface with members xe-0/0/1,xe-1/0/1”
  29. Configure ae2 as a Layer 2 interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 unit 0 family ethernet-switching interface-mode trunk
    user@EX9200-A# set MC_Config_Global interfaces ae2 unit 0 family ethernet-switching vlan members all
  30. Configure the LACP parameters on ae2.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options lacp active
    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options lacp periodic fast
  31. Configure the LACP system ID on ae2.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options lacp system-id 00:01:02:03:04:07
  32. Configure the LACP administrative key on ae2.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options lacp admin-key 2
  33. Configure the MC-AE interface properties on ae2.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae mc-ae-id 2
    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae redundancy-group 1
  34. Specify the mode of ae2 to be active-active.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae mode active-active
  35. Specify the time in seconds to delay bringing the MC-AE interface to the up state after rebooting an MC-LAG peer.

    By delaying the bring-up of the interface until after protocol convergence, you can prevent packet loss during the recovery of failed links and devices. This network configuration example uses a delay time of 520 seconds. This delay time might not be optimal for your network and should be adjusted to fit your network requirements.

    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae init-delay-time 520
  36. Specify that if a peer of the MC-LAG group goes down, the peer that is configured as status-control active becomes the active peer.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae2 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
  37. Add member interfaces to the aggregated Ethernet interface (ae3) that will be used as the MC-LAG interface.Note

    EX9200-B uses the same interface name of xe-0/0/2.

    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces xe-0/0/2 ether-options 802.3ad ae3
  38. Configure the aggregated Ethernet interface (ae3) that will be used as an MC-LAG interface.
    [edit groups]

    user@EX9200-A# set groups MC_Config_Global interfaces ae3 description “MC-LAG interface with members xe-0/0/2 on both switches”
  39. Configure ae3 as a Layer 2 interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 unit 0 family ethernet-switching interface-mode trunk
    user@EX9200-A# set MC_Config_Global interfaces ae3 unit 0 family ethernet-switching vlan members all
  40. Configure the LACP parameters on ae3.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options lacp active
    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options lacp periodic fast
  41. Configure the LACP system ID on ae3.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options lacp system-id 00:01:02:03:04:08
  42. Configure the LACP administrative key on ae3.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options lacp admin-key 3
  43. Configure the MC-AE interface properties on ae3.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae mc-ae-id 3
    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae redundancy-group 1
  44. Specify the mode of ae3 to be active-active.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae mode active-active
  45. Specify the time in seconds to delay bringing the MC-AE interface to the up state after rebooting an MC-LAG peer.

    By delaying the bring-up of the interface until after protocol convergence, you can prevent packet loss during the recovery of failed links and devices. This network configuration example uses a delay time of 520 seconds. This delay time might not be optimal for your network and should be adjusted to fit your network requirements.

    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae init-delay-time 520
  46. Specify that if a peer of the MC-LAG group goes down, the peer that is configured as status-control active becomes the active peer.
    [edit groups]

    user@EX9200-A# set MC_Config_Global interfaces ae3 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-active
  47. Configure VLAN 100 to connect end users.
    [edit groups]

    user@EX9200-A# set MC_Config_Global vlans v100 vlan-id 100
  48. Configure the routed VLAN interface for VLAN 100.
    [edit groups]

    user@EX9200-A# set MC_Config_Global vlans v100 l3-interface irb.100
  49. Enable consistency check.
    [edit groups]

    user@EX9200-A# set MC_Config_Global multi-chassis mc-lag consistency-check
  50. Enable the Rapid Spanning Tree Protocol on the ae2 and ae3 interfaces (MC-LAG interfaces) for optional loop prevention.
    [edit groups]

    user@EX9200-A# set MC_Config_Global protocols rstp interfaces ae2
    user@EX9200-A# set MC_Config_Global protocols rstp interfaces ae3
  51. Configure the RSTP bridge priority.

    Setting the bridge priority to 0 will make the MC-AE nodes of EX9200-A and EX9200-B the best priority.

    [edit groups]

    user@EX9200-A# set MC_Config_Global protocols rstp bridge-priority 0
  52. Configure the RSTP system identifier value.
    [edit groups]

    user@EX9200-A# set MC_Config_Global protocols rstp system-id 00:01:02:03:04:09
  53. Specify the switch service ID.

    The switch service ID is used to synchronize applications, ARP, and MAC learning across MC-LAG members.

    [edit groups]

    user@EX9200-A# set MC_Config_Global switch-options service-id 1
  54. Configure a configuration group for an MC-LAG configuration that applies to the local peer.
    [edit groups]

    user@EX9200-A# set MC_Config_Local
  55. Configure the ICCP interface (ae0) as a Layer 3 interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Local interfaces ae0 unit 0 family inet address 172.16.32.9/30
  56. Specify a unique chassis ID for the MC-LAG (ae2) that the aggregated Ethernet interface belongs to.
    [edit groups]

    user@EX9200-A# set MC_Config_Local interfaces ae2 aggregated-ether-options mc-ae chassis-id 0
  57. Specify the status-control setting of ae2 to be active.
    [edit groups]

    user@EX9200-A# set MC_Config_Local interfaces ae2 aggregated-ether-options mc-ae status-control active
  58. Specify a unique chassis ID for the MC-LAG (ae3) that the aggregated Ethernet interface belongs to.
    [edit groups]

    user@EX9200-A# set MC_Config_Local interfaces ae3 aggregated-ether-options mc-ae chassis-id 0
  59. Specify the status-control setting of ae3 to be active..
    [edit groups]

    user@EX9200-A# set MC_Config_Local interfaces ae3 aggregated-ether-options mc-ae status-control active
  60. Configure a configuration group for an MC-LAG configuration that applies to the remote peer.
    [edit groups]

    user@EX9200-A# set MC_Config_Remote
  61. Configure ae0 as a Layer 3 interface.
    [edit groups]

    user@EX9200-A# set MC_Config_Remote interfaces ae0 unit 0 family inet address 172.16.32.10/30
  62. Specify a unique chassis ID for the MC-LAG (ae2) that the aggregated Ethernet interface belongs to.
    [edit groups]

    user@EX9200-A# set MC_Config_Remote interfaces ae2 aggregated-ether-options mc-ae chassis-id 1
  63. Specify the status-control setting of ae2 to be standby.
    [edit groups]

    user@EX9200-A# set MC_Config_Remote interfaces ae2 aggregated-ether-options mc-ae status-control standby
  64. Specify a unique chassis ID for the MC-LAG (ae3) that the aggregated Ethernet interface belongs to.
    [edit groups]

    user@EX9200-A# set MC_Config_Remote interfaces ae3 aggregated-ether-options mc-ae chassis-id 1
  65. Specify the status-control setting of ae3 to be standby.
    [edit interfaces]

    user@EX9200-A# set MC_Config_Remote interfaces ae3 aggregated-ether-options mc-ae status-control standby
  66. Specify that if a peer of the MC-LAG group goes down, the peer that is configured as status-control active becomes the active peer.
    [edit interfaces]

    user@EX9200-A# set MC_Config_Remote interfaces ae3 aggregated-ether-options mc-ae events iccp-peer-down prefer-status-control-standby
  67. Enable link protection between the two MC-LAG peers.

    Assign interface ae1 to act as the ICL to protect the MC-AE interfaces, ae2 and ae3, in case of failure.

    [edit interfaces]

    user@EX9200-A# set ae2 unit 0 multi-chassis-protection 172.16.32.6 interface ae1
    user@EX9200-A# set ae3 unit 0 multi-chassis-protection 172.16.32.6 interface ae1
  68. Specify the local IP address of the ICCP interface.
    [edit protocols]

    user@EX9200-A# set iccp local-ip-addr 172.16.32.5
  69. Configure the session establishment hold time for ICCP to connect faster.Note

    We recommend 50 seconds as the session establishment hold time value.

    [edit protocols]

    user@EX9200-A# set iccp peer 172.16.32.6 session-establishment-hold-time 50
    user@EX9200-A# set iccp peer 172.16.32.6 redundancy-group-id-list 1
    user@EX9200-A# set iccp peer 172.16.32.6 backup-liveness-detection backup-peer-ip 10.92.76.4
  70. To enable BFD for ICCP, configure the minimum receive interval.

    We recommend a minimum receive interval value of 6 seconds.

    [edit protocols]

    user@EX9200-A# set iccp peer 172.16.32.6 liveness-detection minimum-interval 2000
    user@EX9200-A# set iccp peer 172.16.32.6 liveness-detection multiplier 4


  71. Apply the groups configured earlier, so that the Junos configuration will inherit the statements from the MC_Config_Global, MC_Config_Local, and MC_Config_Remote configuration groups.
    [edit]

    user@EX9200-A# set apply-groups [ MC_Config_Global MC_Config_Local MC_Config_Remote ]

Configuring MC-LAG on EX9200-B

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy.

  1. Create a user account to access the switch, along with a user identifier (UID), a login class, and a password.
    [edit system]

    user@EX9200-A# set login user MCLAG_Admin uid 2000
    user@EX9200-B# set login user MCLAG_Admin class super-user
    user@EX9200-B# set login user MCLAG_Admin authentication encrypted-password “$ABC123”
  2. Statically map EX9200-A to 10.92.76.2 and EX9200-B to 10.92.76.4.
    [edit system]

    user@EX9200-B# set static-host-mapping EX9200-A inet 10.92.76.2
    user@EX9200-B# set static-host-mapping EX9200-B inet 10.92.76.4
  3. Enable NETCONF service using SSH.
    [edit system]

    user@EX9200-B# set services netconf ssh
  4. Enable the peers-synchronize statement to copy and load the MC-LAG configuration from EX9200-B to EX9200-A by default.
    [edit system]

    user@EX9200-B# set commit peers-synchronize
  5. Configure the hostname, usernames, and authentication details for EX9200-A, the peer with which EX9200-B will be synchronizing the MC-LAG configuration.
    [edit system]

    user@EX9200-B# set commit peers EX9200-A user MCLAG_Admin
    user@EX9200-A# set commit peers EX9200-A authentication "$ABC123"
  6. Configure an MC-LAG IRB and configure static Address Resolution Protocol (ARP) on the MC-LAG IRB peers to allow routing protocols to traverse the IRB interface.
    [edit interfaces]

    user@EX9200-B# set irb unit 100 family inet address 192.168.100.3/24 arp 192.168.100.2 l2-interface ae1
    user@EX9200-B# set irb unit 100 family inet address 192.168.100.3/24 arp 192.168.100.2 mac 28:8a:1c:e3:f7:f0
  7. Enable VRRP on the MC-LAGs by assigning a virtual IP address that is shared between each switch in the VRRP group, and assigning an individual IP address for each individual member in the VRRP group.
    [edit interfaces]

    user@EX9200-B# set irb unit 100 family inet address 192.168.100.3/24 vrrp-group 1 virtual-address 192.168.100.1
    user@EX9200-B# set irb unit 100 family inet address 192.168.100.3/24 vrrp-group 1 priority 100
    user@EX9200-B# set irb unit 100 family inet address 192.168.100.3/24 vrrp-group 1 accept-data
  8. Configure a loopback interface.
    [edit interfaces]

    user@EX9200-B# set lo0 unit 0 family inet address 172.16.32.6/32
  9. Configure a default gateway.
    [edit routing-options]

    user@EX9200-B# set static route 0.0.0.0 next-hop 10.92.77.254
  10. Configure an OSPF area that includes the loopback interface and the ICCP interface.
    [edit protocols]

    user@EX9200-B# set ospf area 0.0.0.0 interface lo0 passive
    user@EX9200-B# set ospf area 0.0.0.0 interface ae0
  11. Configure Link Layer Discovery Protocol for all interfaces.
    [edit protocols]

    user@EX9200-B# set lldp interface all
  12. Configure the number of aggregated Ethernet interfaces to be created on EX9200-B.
    [edit chassis]

    user@EX9200-B# set aggregated-devices ethernet device-count 20
  13. Enable link protection between the two MC-LAG peers.

    Assign interface ae1 to act as the ICL to protect the MC-AE interfaces, ae2 and ae3, in case of failure.

    [edit interfaces]

    user@EX9200-B# set ae2 unit 0 multi-chassis-protection 172.16.32.5 interface ae1
    user@EX9200-B# set ae3 unit 0 multi-chassis-protection 172.16.32.5 interface ae1
  14. Specify the local IP address of the ICCP interface.
    [edit protocols]

    user@EX9200-B# set iccp local-ip-addr 172.16.32.6
  15. Configure the session establishment hold time for ICCP to connect faster.Note

    We recommend 50 seconds as the session establishment hold time value.

    [edit protocols]

    user@EX9200-B# set iccp peer 172.16.32.5 session-establishment-hold-time 50
    user@EX9200-B# set iccp peer 172.16.32.5 redundancy-group-id-list 1
    user@EX9200-B# set iccp peer 172.16.32.5 backup-liveness-detection backup-peer-ip 10.92.76.2
  16. To enable BFD for ICCP, configure the minimum receive interval.

    We recommend a minimum receive interval value of 6 seconds.

    [edit protocols]

    user@EX9200-B# set iccp peer 172.16.32.5 liveness-detection minimum-interval 2000
    user@EX9200-B# set iccp peer 172.16.32.5 liveness-detection multiplier 4
  17. Apply the groups configured earlier, so that the Junos configuration will inherit the statements from the MC_Config_Global, MC_Config_Local, and MC_Config_Remote configuration groups.
    [edit]

    user@EX9200-B# set apply-groups [ MC_Config_Global MC_Config_Local MC_Config_Remote ]

Results

Display the results of the configuration on EX9200-A before you commit the configuration.

Display the results of the configuration on EX9200-B before you commit the configuration.

Verification

Verifying ICCP on MC-LAG

Purpose

Verify that ICCP is running on each device in the MC-LAG.

Action

  1. Verify that ICCP is running on EX9200-A.
    user@EX92000-A> show iccp
  2. Verify that ICCP is running on EX9200-B.
    user@EX9200-B> show iccp

Meaning

This output shows that the TCP connection between the peers hosting the MC-LAG is up, liveness detection is up, Backup liveness peer status is up, and LACPD, MCLAG_CFGCHKD,and L2ALD _ICCP_CLIENT client applications are running.

Verifying LACP on MC-LAG

Purpose

Verify that LACP is working properly on each device in the MC-LAG.

Action

  1. Verify that the LACP interfaces are up and running on EX9200-A.
    user@EX9200-A> show lacp interfaces
  2. Verify that the LACP interfaces are up and running on EX9200-B.
    user@EX9200-B> show lacp interfaces

Meaning

This output means that both devices and all related interfaces are properly participating in LACP negotiations.

Verifying Aggregated Ethernet Interfaces in MC-LAG

Purpose

Verify that all of the ae interfaces are configured properly in the MC–LAG.

Action

  1. Verify the ae interfaces on EX9200-A.
    user@EX9200-A> show interfaces mc-ae
  2. Verify the ae interfaces on EX9200-B.
    user@EX9200-B> show interface mc-ae

Meaning

This output means that the mc-ae interfaces on each device are up and active.

Verifying VRRP in MC-LAG

Purpose

Verify that VRRP is up and active between the devices in the MC-LAG.

Action

  1. Confirm that VRRP is up and active on EX9200-A.
    user@EX9200-A> show vrrp

    In this example, Switch A is the master VRRP member.

  2. Confirm that VRRP is up and active on EX9200-B.
    user@EX9200-B> show vrrp

    In this example, Switch B is the backup VRRP member.

Meaning

This output means that VRRP is up and running properly.

Verifying OSPF on MC-LAG

Purpose

Verify that OSPF is properly up and running with MC-LAG.

Action

  1. Show the OSPF neighbors on EX9200-A.
    user@EX9200-A> show ospf neighbor
  2. Show the OSPF routing table on EX9200-A.
    user@EX9200-A> show ospf route
  3. Show the OSPF neighbors on EX9200-B.
    user@EX9200-B> show ospf neighbor
  4. Show the OSPF routing table on EX9200-B.
    user@EX9200-B> show ospf route

Meaning

The output shows that the neighboring devices are fully adjacent.

Verifying that Configuration Consistency Check Passed

Purpose

View the list of committed MC-LAG parameters that are checked for inconsistencies, the consistency requirement (identical or unique), the enforcement level (mandatory or desired), and the result of the configuration consistency check. The results are either pass or fail.

Action

  1. Show the list of committed MC-LAG parameters that passed or failed configuration consistency check on EX9200-A.
    user@EX9200-A> show multi-chassis mc-lag configuration-consistency
  2. Show the list of committed MC-LAG parameters that passed or failed configuration consistency check on EX9200-B.
    user@EX9200-B> show multi-chassis mc-lag configuration-consistency

Meaning

The output shows that all configured and committed MC-LAG parameters have passed configuration consistency check.

Verifying the Configuration Consistency Check Status for the Global Configuration

Purpose

View configuration consistency check status for all committed global configuration related to MC-LAG functionality, the consistency requirement (identical or unique), the enforcement level (mandatory or desired), and the result of the configuration consistency check. The results are either pass or fail.

This command shows only a subset of what is shown in the show multi-chassis mc-lag configuration-consistency command. The following parameters related to the global configuration are checked for consistency.

  • ICL interface

  • RSTP bridge priority

  • service ID

  • session establishment hold time

  • local IP address of the ICCP interface

  • backup liveness detection peer IP address

  • ICCP/BFD multiplier

Parameters specific to the ICL, MC-LAG interfaces, and VLAN and VRRP configurations are shown later in this document.

Action

  1. Show the list of committed global configuration parameters that passed or failed configuration consistency check on EX9200-A.

    The output below shows all of the parameters that directly affect the MC-LAG configuration.

    user@EX9200-A> show multi-chassis mc-lag configuration-consistency global-config
  2. Show the list of committed global configuration parameters that passed or failed configuration consistency check on EX9200-B
    user@EX9200-B> show multi-chassis mc-lag configuration-consistency global-config

Meaning

The output shows that the committed global configuration related to MC-LAG have passed configuration consistency check.

Verifying the Configuration Consistency Check Status for the Interchassis Control Link

Purpose

View configuration consistency check status for parameters related to the ICL, the consistency requirement (identical or unique), the enforcement level (mandatory or desired), and the result of the configuration consistency check. The results are either pass or fail. Some example of parameters related to the ICL interface are the interface mode and which VLAN the interface belongs to.

This command shows only a subset of what is shown in the show multi-chassis mc-lag configuration-consistency command. The following parameters related to the ICL configuration are checked for consistency check:

  • VLAN membership

  • interface mode

Action

  1. Show the list of committed ICL configuration parameters that passed or failed configuration consistency check on EX9200-A
    user@EX9200-A> show multi-chassis mc-lag configuration-consistency icl-config
  2. Show the list of committed ICL configuration parameters that passed or failed configuration consistency check on EX9200-B
    user@EX9200-B> show multi-chassis mc-lag configuration-consistency icl-config

Meaning

The output shows that the committed MC-LAG parameters related to the ICL have passed configuration consistency check.

Verifying the Configuration Consistency Check Status for the MC-LAG Interfaces

Purpose

View configuration consistency check status for committed parameters related to the multichassis aggregated Ethernet interfaces, the consistency requirement (identical or unique), the enforcement level (mandatory or desired), and the result of the configuration consistency check. The results are either pass or fail.

This command shows only a subset of what is shown in the show multi-chassis mc-lag configuration-consistency command. The following parameters related to the MC-AE interfaces are checked for consistency:

  • LACP administrative key

  • LACP system ID

  • LACP periodic interval

  • prefer status control setting

  • status control setting

  • mode

  • chassis ID

  • redundancy group ID

  • VLAN membership of the ICL

  • interface mode of the ICL

Action

  1. Show the list of committed MC-LAG interface configuration parameters that passed or failed configuration consistency check on EX9200-A.
    user@EX9200-A> show multi-chassis mc-lag configuration-consistency mcae-config
  2. Show the list of committed MC-LAG interface configuration parameters that passed or failed configuration consistency check on EX9200-B.
    user@EX9200-B> show multi-chassis mc-lag configuration-consistency mcae-config

Meaning

The output shows that the committed MC-LAG parameters related to the MC-AE interfaces have passed configuration consistency check.

Verifying the Configuration Consistency Check Status for the VLAN Configuration

Purpose

View configuration consistency check status for committed parameters related to MC-LAG VLAN configuration, the consistency requirement (identical or unique), the enforcement level (mandatory or desired), and the result of the configuration consistency check. The results are either pass or fail.

This command shows only a subset of what is shown in the show multi-chassis mc-lag configuration-consistency command. The following parameters related to the VLAN and IRB configuration are checked for consistency:

  • VRRP group ID

  • IP address of IRB interface

Action

  1. Show the list of committed VLAN configuration parameters that passed or failed configuration consistency check on EX9200-A.
    user@EX9200-A> show multi-chassis mc-lag configuration-consistency vlan-config
  2. Show the list of committed VLAN configuration parameters that passed or failed configuration consistency check on EX9200-B.
    user@EX9200-B> show multi-chassis mc-lag configuration-consistency vlan-config

Meaning

The output shows that the committed MC-LAG parameters related to the VLAN and IRB configurations have passed configuration consistency check.

Verifying the Configuration Consistency Check Status for VRRP

Purpose

View configuration consistency check status for committed parameters related to VRRP configuration, the consistency requirement (identical or unique), the enforcement level (mandatory or desired), and the result of the configuration consistency check. The results are either pass or fail.

This command shows only a subset of what is shown in the show multi-chassis mc-lag configuration-consistency command. The following parameters related to the VRRP configuration are checked for consistency: VRRP group virtual IP address and VRRP group priority value.

Action

  1. Show the list of committed VRRP configuration parameters that passed or failed configuration consistency check on EX9200-A.
    user@EX9200-A> show multi-chassis mc-lag configuration-consistency vrrp-config
  2. Show the list of committed VRRP configuration parameters that passed or failed configuration consistency check on EX9200-B.
    user@EX9200-B> show multi-chassis mc-lag configuration-consistency vrrp-config

Meaning

The output shows that the committed MC-LAG parameters related to VRRP configuration have passed configuration consistency check.