[j-nsp] EVPN VGA MAC address learning cause flooding

[Cathal Mooney]

Interesting discussion here.  I take it this is not just an issue for
packets *originated* by the switch (as in generated by the switch),
but also routed packets it forwards?

Sounds like the config posted hard-coding the MAC is a sensible thing
to do.  I'm pondering now, in a situation with multiple vlans / irb
interfaces on a device, if there is any requirement to set a different
VG MAC for each one?  Seems I could use, for instance, the two in the
example for every irb/vlan and not have any conflict?

thanks,

Cathal.



On Tue, 7 Dec 2021 at 15:48, Roger Wiklund via juniper-nsp
<juniper-nsp at puck.nether.net> wrote:
>
> Hi
>
> Yes you need to set the vga-v4/v6-mac on the IRB interface:
>
> virtual-gateway-v4-mac | EVPN User Guide | Juniper Networks TechLibrary
> <https://www.juniper.net/documentation/us/en/software/junos/evpn-vxlan/topics/ref/statement/virtual-gateway-v4-mac-edit-interfaces.html>
>
> eg:
>
> set interfaces irb.x virtual-gateway-v4-mac 00:00:5e:44:44:44
> set interfaces irb.x virtual-gateway-v6-mac 00:00:5e:66:66:66
>
> Regards
> Roger
>
> On Sun, Nov 21, 2021 at 12:46 PM Chen Jiang via juniper-nsp <
> juniper-nsp at puck.nether.net> wrote:
>
> > Hi! Experts
> >
> > Sorry for disturbing, I am curious why IRB interface in EVPN does not use
> > VGAs' Virtual MAC address (00:00:5e:00:01:01)  to originate packets,  but
> > instead uses the interface real MAC address to originate packets.
> >
> > Are there any special thoughts behind this? It will cause BUM flooding if
> > peer is a layer 2 switch ( peer s will never learn VGA virtual MAC address)
> >
> > Thanks for your help!
> >
> > --
> > BR!
> >
> >
> >
> >            James Chen
> > _______________________________________________
> > juniper-nsp mailing list juniper-nsp at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/juniper-nsp
> >
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