Strange issue I suspect is related to possible LACP sharing method mismatch between Avaya ERS5xxx and XOS on x440's. 8 x440's connected back using port 47/48 to a Nortel/Avaya ERS core using LACP. Also a stack of 5 x450G2's which are used as a voice stack (tagged voice vlan over LACP trunk to core, where VMware hosts a virtual IPOffice). The latter has 4 ports in LACP to core. Was having an issue where phones (30) could not connect to IPOffice during provisioning. I could not ping a phone, but could see it in the FDB. Added a VIP in the voice VLAN on the x450 stack and still could not ping the phone. I could see it in the IPARP cache and could still see it in the FDB.
Looked in the arp cache from the core side, it showed via trunk 28 (the LACP back to the voip stack). I looked in our firewall (connected to the core on that VLAN, but not routing or anything) and it too showed it in the ARP cache.
On a whim, disabled 2 of the 4 ports on the core side (both in the same switch [2 ports were in switch 1 and 2 in switch 4; disabled the two in switch 4]). After about 5 minutes, the ping from the VIP to the phone began working. So...
What role would LACP play in a switch where a VIP is directly tied to the VLAN of a device in the same switch/stack? While troubleshooting, found a similar problem on one of the x440's where a VDI machine could ping a printer, but another VDI machine on the same VMhost could not. In this case it was across the core (VDI/VM -- CORE -- X440 via LACP -- PRINTER) but the same fix worked - turned off one of the two ports in LACP on the core side.
This leads me to think it's a LAG mismatch but still does not explain the scenario where the VIP could not ping a local device in the same VLAN. Thoughts?