Example of MLAG Configuration

Below is an example of how to configure an MLAG. The following figure shows a finished MLAG network.

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Simple MLAG Configuration
../Graphics/EX_ports_0050.svg
  1. Create the Inter-Switch Connection (ISC).

    Description: The ISC provides an out-of-band IP communications path between the two MLAG peer switches to exchange keep-alive packets and to checkpoint various state information between switches.

    On the “Left” BlackDiamond 8800 switch:

    enable sharing 2:1 group 2:1,3:1
    create vlan isc
    config vlan isc tag 3000
    config vlan isc add port 2:1 tag
    config vlan isc ipaddress 1.1.1.1/24

    On the “Right” BlackDiamond 8800 switch:

    enable sharing 2:1 group 2:1,3:1
    create vlan isc
    config vlan isc tag 3000
    config vlan isc add port 2:1 tag
    config vlan isc ipaddress 1.1.1.2/24
  2. Create the MLAG peer and associate the peer switch's IP address.

    Description: By creating an MLAG peer you associate a peer name that can be associated with the peer switch's IP address and other peer configuration properties. The peer is then bound to each individual MLAG port group.

    On the “left” BlackDiamond 8800 switch:

    create mlag peer "rightBD8K"
    config mlag peer “rightBD8K” ipaddress 1.1.1.2

    On the “right” BlackDiamond 8800 switch:

    create mlag peer “leftBD8K”
    config mlag peer "leftBD8K" ipaddress 1.1.1.1
  3. Create the MLAG port groups.

    Description: Creates an MLAG port group by specifying the local switch's port, the MLAG peer switch, and an "mlag-id" which is used to reference the corresponding port on the MLAG peer switch. The specified local switch's port can be either a single port or a load share master port.

    On the “left” BlackDiamond 8800 switch:

    enable mlag port 1:1 peer "rightBD8K" id 1
    enable mlag port 1:2 peer "rightBD8K" id 2

    On the “right” BlackDiamond 8800 switch:

    enable mlag port 1:2 peer "leftBD8K" id 1
    enable mlag port 1:1 peer "leftBD8K" id 2
  4. Verify MLAG peers and ports are operational.

    Description: After MLAG groups are configured, you can verify the connections via the show mlag peer and show mlag ports commands. Be sure to note the peer status, the Local Link State, and the Remote Link status.

    On the “left” BlackDiamond 8800 switch:
    BD-8810.5 # show mlag peer
    Multi-switch Link Aggregation Peers:
    MLAG Peer         : leftBD8k
    VLAN              : isc             Virtual Router    : VR-Default
    Local IP Address  : 1.1.1.2         Peer IP Address   : 1.1.1.1
    MLAG ports        : 2               Tx-Interval       : 1000 ms
    Checkpoint Status : Up              Peer Tx-Interval  : 1000 ms
    Rx-Hellos         : 184             Tx-Hellos         : 184
    Rx-Checkpoint Msgs: 12              Tx-Checkpoint Msgs: 12
    Rx-Hello Errors   : 0               Tx-Hello Errors   : 0
    Hello Timeouts    : 1               Checkpoint Errors : 0
    Up Time           : 0d:0h:0m:10s    Peer Conn.Failures: 1
    
    BD-8810.3 # show mlag ports
    Local  
                                                   Local  Remote
    MLAG          Local   Link     Remote                  Peer    Fail    Fail
    Id            Port    State    Link    Peer            Status  Count   Count
    ============================================================================
    1       1:1     A        Up          rightBD8K          Up       0       0
    2       1:2     A        Up          rightBD8K          Up       0       0
    ============================================================================
    Local Link State: A - Active, D - Disabled, R - Ready, NP - Port not present
    Remote Link     : Up - One or more links are active on the remote switch,
    Down - No links are active on the remote switch,
    N/A - The peer has not communicated link state for this MLAG port
    Number of Multi-switch Link Aggregation Groups  : 2
    Convergence control                             : Fast
    On the “right” BlackDiamond 8800 switch:
    BD-8810.3 # show mlag peer
    Multi-switch Link Aggregation Peers:
    MLAG Peer         : rightBD8k
    VLAN              : isc             Virtual Router    : VR-Default
    Local IP Address  : 1.1.1.1         Peer IP Address   : 1.1.1.2
    MLAG ports        : 2               Tx-Interval       : 1000 ms
    Checkpoint Status : Up              Peer Tx-Interval  : 1000 ms
    Rx-Hellos         : 167             Tx-Hellos         : 167
    Rx-Checkpoint Msgs: 12              Tx-Checkpoint Msgs: 12
    Rx-Hello Errors   : 0               Tx-Hello Errors   : 0
    Hello Timeouts    : 1               Checkpoint Errors : 0
    Up Time           : 0d:0h:0m:7s     Peer Conn.Failures: 1
    
    BD-8810.5 # show mlag ports
    Local                                          Local Remote
    MLAG        Local   Link     Remote            Peer    Fail    FailId
                Port    State    Link    Peer      Status  Count   Count
    =====================================================================
    2     1:1   A        Up              leftBD8K   Up     0       0
    1     1:2   A        Up              leftBD8K   Up     0       0
    ======================================================================
    Local Link State: A - Active, D - Disabled, R - Ready, NP - Port not 
    present
    Remote Link     : Up - One or more links are active on the remote switch,
    Down - No links are active on the remote switch,
    N/A - The peer has not communicated link state for this MLAGport
    Number of Multi-switch Link Aggregation Groups  : 2
    Convergence control                             : Fast
  5. Add ISC port to VLAN.

    Description: The ISC port must be added as a member port for any VLAN that has MLAG member ports.

    create vlan "xyz"

    On the “left” BlackDiamond 8800 switch:

    configure vlan "xyz" add port 1:1, 2:1 tagged

    On the “right” BlackDiamond 8800 switch:

    configure vlan "xyz" add port 1:2, 2:1 tagged

    The previous figure, the example above, shows a basic MLAG network. The following figure shows a network with back-to-back aggregation. There is one MLAG configured on the BlackDiamond switches and three configured on the Summit switches.

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    Two-tier MLAG Network
    ../Graphics/EX_ports_0051.svg