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    Creating and Managing Multichassis Link Aggregation Groups (MC-LAGs)

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

    The MC-LAG routers use the Interchassis Control Protocol (ICCP) to exchange the control information between two MC-LAG routers.

    On one end of an MC-LAG 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 detect the MC-LAG. On the other side of MC-LAG are two MC-LAG routers. Each of the routers has one or more physical links connected to a single client device. The routers coordinate with each other to ensure that data traffic is forwarded properly.

    To start creating an MC-LAG:

    1. Click the Build Mode icon in the Connectivity Services Director banner.
    2. Select Wired > Tasks > Create MC-LAG in the Tasks pane.

      The Create MC-LAG wizard opens to the Device Selections page.

    3. Continue with the section Selecting Devices for the MC-LAG.

    This topic includes:

    Selecting Devices for the MC-LAG

    To select devices for the MC-LAG in the Device Selections page:

    1. Click Select Devices.

      The Select Two Devices for MC-LAG window opens, listing the devices on which you can create an MC-LAG.

    2. Select two devices from the list.

      Both devices must have the same Family Type. You cannot mix ELS and non-ELS devices.

    3. Click Done.

      The devices appear in the Devices selected for MC-LAG list.

    4. Click either Next or MC-LAG Settings.

      The MC-LAG Settings page opens. Continue with the section Configuring MC-LAG Settings.

    Configuring MC-LAG Settings

    On the MC-LAG Settings page you configure MC-LAG and ICCP settings for both selected routers. Some MC-LAG and ICCP settings must be coordinated between the two routers, so when you specify such a setting for one router, that setting is automatically specified for the other router.

    To configure MC-LAG settings:

    1. Enter settings in the MC-LAG section for both routers.

      The MC-LAG settings configure the connection between the client device and the router. Table 1 describes the fields in this section.

    2. Enter settings in the ICCP-LAG section for both routers.

      The ICCP settings configure the connection between the peer routers in the MC-LAG. Table 2 describes the fields in this section.

    3. Select the ports for the MC-LAG and the ICCP LAG in the Port Selection section.

      Each selected device has a tab. For each device, move ports between the Available Ports list and the MC-LAG or ICCP-LAG lists by using the arrow keys.

    4. Click Finish

    Table 1: MC-LAG Settings

    Field

    Description

    AE Name

    Select the aggregated Ethernet interface to use in the MC-LAG.

    LACP Mode

    Select the LACP mode for the MC-LAG.

    Description

    Enter a description for the MC-LAG.

    VLAN

    Select the same VLAN profile to associate to the aggregated Ethernet (ae) interface on each router.

    LACP System ID

    Specify the same LACP system ID on each router.

    LACP Admin Key

    Specify the same LACP administration key on each router.

    AE ID

    Specify the same multichassis aggregated Ethernet identification number for the MC-LAG that the aggregated Ethernet interface belongs to on each router.

    Chassis ID

    Specify a unique chassis ID for the MC-LAG that the aggregated Ethernet interface belongs to on each router.

    Control Status

    Specify whether the aggregated Ethernet interface participating in the MC-LAG is primary or secondary. Primary is active, and secondary is standby.

    Init Delay Time (seconds)

    Specify an initialization delay time, in seconds.

    Table 2: ICCP-LAG Settings

    Field

    Description

    AE Name

    Select the aggregated Ethernet interface to use for the ICCP connection.

    LACP Mode

    Select the LACP mode for the ICCP connection.

    Description

    Enter a description for the ICCP connection.

    VLAN Name

    Enter the name of the VLAN to use for the ICCP connection.

    Vlan ID

    Enter the same VLAN ID to use for the ICCP connection on each router.

    Local IP

    Configure the local IP address to be used by all routers hosting the MC-LAG.

    Liveness min. receive interval (ms)

    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.

    Liveness min. transmit interval (ms)

    Configure the minimum transmit interval during which a router must receive a reply from a router with which it has established a BFD session.

    Session establish hold time (ms)

    Configure the time during which an ICCP connection must succeed between the routers hosting the MC-LAG. Configured session establishment hold time results in faster ICCP connection establishment. The recommended value is 50 seconds.

    Managing MC-LAGs

    You manage MC-LAGs by using the Manage LAG task.

    What to Do Next

    The configuration changes that you make in the Build mode are not deployed to devices automatically. After you create an MC-LAG, you must deploy it on the routers. You must manually deploy the changes to devices in Deploy mode.

    Tip: Even though MC-LAG configuration is not contained within a profile, you can view the MC-LAGs assigned to a router by using the View Assigned Profiles task in Build mode.

    Modified: 2017-09-13