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Example: EVPN-MPLS Interworking With an MC-LAG Topology

 

This example shows how to use Ethernet VPN (EVPN) to extend a multichassis link aggregation (MC-LAG) network over an MPLS network to a data center network or geographically distributed campus network.

EVPN-MPLS interworking is supported with an MC-LAG topology in which two MX Series routers, two EX9200 switches, or a mix of the two Juniper Networks devices function as MC-LAG peers, which use the Inter-Chassis Control Protocol (ICCP) and an interchassis link (ICL) to connect and maintain the topology. The MC-LAG peers are connected to a provider edge (PE) device in an MPLS network. The PE device can be either an MX Series router or an EX9200 switch.

This example shows how to configure the MC-LAG peers and PE device in the MPLS network to interwork with each other.

Requirements

This example uses the following hardware and software components:

  • Three EX9200 switches:

    • PE1 and PE2, which both function as MC-LAG peers in the MC-LAG topology and EVPN BGP peers in the EVPN-MPLS overlay network.

    • PE3, which functions as an EVPN BGP peer in the EVPN-MPLS overlay network.

  • The EX9200 switches are running Junos OS Release 17.4R1 or later software.

Note

Although the MC-LAG topology includes two customer edge (CE) devices, this example focuses on the configuration of the PE1, PE2, and PE3.

Overview and Topology

Figure 1 shows an MC-LAG topology with provider edge devices PE1 and PE2 that are configured as MC-LAG peers. The MC-LAG peers exchange control information over an ICCP link and data traffic over an ICL. In this example, the ICL is an aggregated Ethernet interface that is comprised of two interfaces.

Figure 1: EVPN-MPLS Interworking With an MC-LAG Topology
EVPN-MPLS Interworking With an
MC-LAG Topology

The topology in Figure 1 also includes CE devices CE1 and CE2, which are both multihomed to each PE device. The links between CE1 and the two PE devices are bundled as an aggregated Ethernet interface on which MC-LAG in active-active mode is configured.

The topology in Figure 1 also includes PE3 at the edge of an MPLS network. PE3 functions as the gateway between the MC-LAG network and either a data center or a geographically distributed campus network. PE1, PE2, and PE3 run EVPN, which enables hosts in the MC-LAG network to communicate with hosts in the data center or other campus network by way of an intervening MPLS network.

From the perspective of the EVPN-MPLS interworking feature, PE3 functions solely as an EVPN BGP peer, and PE1 and PE2 in the MC-LAG topology have dual roles:

  • MC-LAG peers in the MC-LAG network.

  • EVPN BGP peers in the EVPN-MPLS network.

Because of the dual roles, PE1 and PE2 are configured with MC-LAG, EVPN, BGP, and MPLS attributes.

Table 1 outlines key MC-LAG and EVPN (BGP and MPLS) attributes configured on PE1, PE2, and PE3.

Table 1: Key MC-LAG and EVPN (BGP and MPLS) Attributes Configured on PE1, PE2, and PE3

Key Attributes

PE1

PE2

PE3

MC-LAG Attributes

Interfaces

ICL: aggregated Ethernet interface ae1, which is comprised of xe-2/1/1 and xe-2/1/2

ICCP: xe-2/1/0

ICL: aggregated Ethernet interface ae1, which is comprised of xe-2/1/1 and xe-2/1/2

ICCP: xe-2/1/0

Not applicable

EVPN-MPLS

Interfaces

Connection to PE3: xe-2/0/0

Connection to PE2: xe-2/0/2

Connection to PE3: xe-2/0/2

Connection to PE1: xe-2/0/0

Connection to PE1: xe-2/0/2

Connection to PE2: xe-2/0/3

IP addresses

BGP peer address: 198.51.100.1

BGP peer address: 198.51.100.2

BGP peer address: 198.51.100.3

Autonomous system

65000

65000

65000

Virtual switch routing instances

evpn1, evpn2, evpn3

evpn1, evpn2, evpn3

evpn1, evpn2, evpn3

Note the following about the EVPN-MPLS interworking feature and its configuration:

  • You must configure Ethernet segment identifiers (ESIs) on the dual-homed interfaces in the MC-LAG topology. The ESIs enable EVPN to identify the dual-homed interfaces.

  • The only type of routing instance that is supported is the virtual switch instance (set routing-instances name instance-type virtual-switch).

  • On the MC-LAG peers, you must include the bgp-peer configuration statement in the [edit routing-instances name protocols evpn mclag] hierarchy level. This configuration statement enables the interworking of EVPN-MPLS with MC-LAG on the MC-LAG peers.

  • Address Resolution Protocol (ARP) suppression is not supported.

PE1 and PE2 Configuration

To configure PE1 and PE2, perform these tasks:

CLI Quick Configuration

PE1: MC-LAG Configuration

PE1: EVPN-MPLS Configuration

PE2: MC-LAG Configuration

PE2: EVPN-MPLS Configuration

PE1: Configuring MC-LAG

Step-by-Step Procedure

  1. Set the number of aggregated Ethernet interfaces on PE1.

  2. Configure aggregated Ethernet interface ae0 on interface xe-2/0/1, and configure LACP and MC-LAG on ae0. Divide aggregated Ethernet interface ae0 into three logical interfaces (ae0.1, ae0.2, and ae0.3). For each logical interface, specify an ESI, place the logical interface is in MC-LAG active-active mode, and map the logical interface to a VLAN.

  3. Configure physical interface xe-2/0/6, and divide it into three logical interfaces (xe-2/0/6.1, xe-2/0/6.2, and xe-2/0/6.3). Map each logical interface to a VLAN.

  4. Configure physical interface xe-2/1/0 as a Layer 3 interface, on which you configure ICCP. Specify the interface with the IP address of 203.0.113.2 on PE2 as the ICCP peer to PE1.

  5. Configure aggregated Ethernet interface ae1 on interfaces xe-2/1/1 and xe-2/1/2, and configure LACP on ae1. Divide aggregated Ethernet interface ae1 into three logical interfaces (ae1.1, ae1.2, and ae1.3), and map each logical interface to a VLAN. Specify ae1 as the multichassis protection link between PE1 and PE2.

PE1: Configuring EVPN-MPLS

Step-by-Step Procedure

  1. Configure the loopback interface, and the interfaces connected to the other PE devices.

  2. Configure IRB interfaces irb.1, irb.2, and irb.3.

  3. Assign a router ID and the autonomous system in which PE1, PE2, and PE3 reside.

  4. Enable per-packet load-balancing for EVPN routes when EVPN multihoming active-active mode is used.

  5. Enable MPLS on interfaces xe-2/0/0.0 and xe-2/0/2.0.

  6. Configure an IBGP overlay that includes PE1, PE2, and PE3.

  7. Configure OSPF as the internal routing protocol for EVPN by specifying an area ID and interfaces on which EVPN-MPLS is enabled.

  8. Configure the Label Distribution Protocol (LDP) on the loopback interface and the interfaces on which EVPN-MPLS is enabled.

  9. Configure virtual switch routing instances for VLAN v1, which is assigned VLAN IDs of 1, 2, and 3, and include the interfaces and other entities associated with the VLAN.

PE2: Configuring MC-LAG

Step-by-Step Procedure

  1. Set the number of aggregated Ethernet interfaces on PE2.

  2. Configure aggregated Ethernet interface ae0 on interface xe-2/0/1, and configure LACP and MC-LAG on ae0. Divide aggregated Ethernet interface ae0 into three logical interfaces (ae0.1, ae0.2, and ae0.3). For each logical interface, specify an ESI, place the logical interface is in MC-LAG active-active mode, and map the logical interface to a VLAN.

  3. Configure physical interface xe-2/0/6, and divide it into three logical interfaces (xe-2/0/6.1, xe-2/0/6.2, and xe-2/0/6.3). Map each logical interface to a VLAN.

  4. Configure physical interface xe-2/1/0 as a Layer 3 interface, on which you configure ICCP. Specify the interface with the IP address of 203.0.113.1 on PE1 as the ICCP peer to PE2.

  5. Configure aggregated Ethernet interface ae1 on interfaces xe-2/1/1 and xe-2/1/2, and configure LACP on ae1. Divide aggregated Ethernet interface ae1 into three logical interfaces (ae1.1, ae1.2, and ae1.3), and map each logical interface to a VLAN. Specify ae1 as the multichassis protection link between PE1 and PE2.

PE2: Configuring EVPN-MPLS

Step-by-Step Procedure

  1. Configure the loopback interface, and the interfaces connected to the other PE devices.

  2. Configure IRB interfaces irb.1, irb.2, and irb.3.

  3. Assign a router ID and the autonomous system in which PE1, PE2, and PE3 reside.

  4. Enable per-packet load-balancing for EVPN routes when EVPN multihoming active-active mode is used.

  5. Enable MPLS on interfaces xe-2/0/0.0 and xe-2/0/2.0.

  6. Configure an IBGP overlay that includes PE1, PE2, and PE3.

  7. Configure OSPF as the internal routing protocol for EVPN by specifying an area ID and interfaces on which EVPN-MPLS is enabled.

  8. Configure the Label Distribution Protocol (LDP) on the loopback interface and the interfaces on which EVPN-MPLS is enabled.

  9. Configure virtual switch routing instances for VLAN v1, which is assigned VLAN IDs of 1, 2, and 3, and include the interfaces and other entities associated with the VLAN.

PE3 Configuration

CLI Quick Configuration

PE3: EVPN-MPLS Configuration

PE3: Configuring EVPN-MPLS

Step-by-Step Procedure

  1. Configure the loopback interface, and the interfaces connected to the other PE devices.

  2. Configure interface xe-2/0/6, which is connected to the host.

  3. Configure IRB interfaces irb.1, irb.2, and irb.3.

  4. Assign a router ID and the autonomous system in which PE1, PE2, and PE3 reside.

  5. Enable per-packet load-balancing for EVPN routes when EVPN multihoming active-active mode is used.

  6. Enable MPLS on interfaces xe-2/0/2.0 and xe-2/0/3.0.

  7. Configure an IBGP overlay that includes PE1, PE2, and PE3.

  8. Configure OSPF as the internal routing protocol for EVPN by specifying an area ID and interfaces on which EVPN-MPLS is enabled.

  9. Configure the LDP on the loopback interface and the interfaces on which EVPN-MPLS is enabled.

  10. Configure virtual switch routing instances for VLAN v1, which is assigned VLAN IDs of 1, 2, and 3, and include the interfaces and other entities associated with the VLAN.