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MCLAG static system MAC

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Rares Hornet
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Hi guys,

I'm having LACP issues with some HP gear connected over MCLAG between 2 x AS7326-56X switches. LACP trunks on my HP switches fail due to peer address changes as sonic MCLAG switches the system MAC address from the Active one to the Standby peer. The LACP trunk gets blocked for about 30-45 seconds when the Active MCLAG switch goes down. The same thing happens again when the Active switch comes back online although the LACP outage is more like 15 seconds this time.

I see that Dell's sonic build has an option called mclag-system-mac that can be statically set up so the lacp peers see the same MAC address in case one of the switches goes down.

Is something like this available on ecSONIC builds? I can't seem to find any docs or info on this topic.

Cheers!

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    Rares Hornet

    I was looking at the mc-lag HLD on the azure github repo and I'm not sure if I understand correctly but this might not be implemented?!

    ```

    4. Design considerations

    • MCLAG domain consists of only two systems.
    • Each system only join one MC-LAG domain
    • Supports Known Unicast and BUM traffic
    • L3 interface on MLAG ports will have vMAC generated from VRRP algorithm using the same IP address assigned to the L3 LIF (logical interface)；(Not supported currently)
    • ARP reply and ND advertisement packet sync-up between MC-LAG peers
    • FDB sync-up between MC-LAG peers
    • Support pure L2 MC-LAG port and MC-LAG L3 routed port or MC-LAG L2 port joining L3 vlan interface

    [caveat: vlan interface does not go down when the last port in the vlan goes down, need further discussion in the community with regarding the 1Q or 1D model]

    The features below are not supported currently, may provide solutions in future releases.

    • More consistency checking, both between peer switches and MLAG port channels configured on the switches, e.g. port speed configuration
    • Peer-link with a detection mechanism, and with robust "split brain" detection
    • Configurable peer master/slave roles for the peer switches
    • VRRP/VARP for active/active gateway redundancy
    • Add feature support across MLAGs (e.g. STP, IGMP snooping, DHCP Relay)
    • Make sure isolation ACL is installed in the ASIC table before MCLAG enabled portchannel is active

    ```

     

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