5820-24XG & gratuitous ARP

[Stefan Neher]

Hi everybody,

i configured two brand new 5820-24XG with irf as core switches.
everything works fine so far, except one thing:

the switches act as routers, the default route points to a firewall cluster.
when there's a failover from firewall node 1 to firewall node 2, the mac adress of the cluster ip changes.
the firewall send gratuitous ARPs, to make the switches being aware of the new mac adress. i double-checked it with wireshark.
the 5820-24XG are configured with "gratuitous-arp-learning enable" by default.
but the 5820-24XG ignore it. there's still the wrong mac adress in the arp table. it set the arp cache lifetime to one minute to minimize the routing outage. i didn't configure any arp security, so i believe gratuitous-arp-learning should work.

Any suggestions are appreciated...

[manuel.bitzi]

Hi Stefan

I've tested it with our 5820 (R1211p04) and the unix tool arping. Works great.

What type of firewall do you use? Whats the gratuitous arp packet like?

br

Manuel