ARP/MAC Tables Not Updating on Core Switches After F5 LTM Failover (GARP Issue?)

We ran into a similar issue. Several Virtual Servers on different VLANs that did not have SelfIPs or Floating IPs configured. In our situation, allocating SIPs/FIPs for those VLANs was not an option, because we were migrating specific virtual servers from one Data Center to another (not the networks) and did not want to readdress the virtual servers. Migrating DNS virtual servers.

Our solution was to allocate SIPs/FIPs from the 198.51.100.0/24, which is a reserved subnet Assigned as "TEST-NET-2" for use in documentation and examples. It should not be used publicly.[7]

On failover, a gARP is issued for these addresses. Since there is no virtual servers, SNATs or anything else route-able or listening, the response is not required. But the gARP for those addresses triggers the failover from the switch perspective to the STANDBY port-channel.

Failover for the virtual servers is instant.

MAC Masquerade is enabled for the traffic group.