Switching

IMPORTANT MODERATION NOTICE

This community is currently under full moderation, meaning  all posts will be reviewed before appearing in the community. Please expect a brief delay—there is no need to post multiple times. If your post is rejected, you'll receive an email outlining the reason(s). We've implemented full moderation to control spam. Thank you for your patience and participation.



  • 1.  EVPN VGAs Virtual MAC address to originate packets

    Posted 14 days ago
    Hi! Experts

    By default, the IRB interface in EVPN does not use VGAs' Virtual MAC address (00:00:5e:00:01:01)  to originate packets, it use interface real MAC address to originate packets instead .

    Are there any special thoughts behind this? cause it will cause BUM flooding if peer is a layer 2 switch.

    Thanks for your help!


  • 2.  RE: EVPN VGAs Virtual MAC address to originate packets

     
    Posted 14 days ago
    Correct, that's why you need to configure the v4-gateway MAC.

    unit 80 {
        virtual-gateway-accept-data;
        family inet {
            address 192.168.0.2/24 {
                preferred;
                virtual-gateway-address 192.168.0.1;
            }
        }
        virtual-gateway-v4-mac 00:00:5e:00:53:01;
    ​



  • 3.  RE: EVPN VGAs Virtual MAC address to originate packets

    Posted 9 days ago
    Yes, I konw this knob, but I don't get the logical behind the JUNOS default behaviour.


  • 4.  RE: EVPN VGAs Virtual MAC address to originate packets

    Posted 13 days ago
    This is indeed a big problem if you're using non-EVPN devices in your fabric. You will need to enable manual MAC address override as smicker suggested. In terms of how this impacts traffic, it's important to understand the forwarding behavior.  The leaf will install the next-hop for the ESI gateway segment if the VGA MAC is used. Meaning the leaf will load-balance to the gateway devices (per flow). If the unicast MAC is used, then you will not load-balance, rather you will send traffic directly on the VTEP tunnel. Although you will still load balance in the fabric. 

    I did write a little article on how load-balancing works > EVPN-VXLAN | Virtual Gateway |QFX5k Forwarding | JUNOS – DAN HEARTY (wordpress.com)

    ------------------------------
    DANIEL HEARTY
    Principal Engineer
    ------------------------------