We recently migrated a pair of 4451 CUBE routers into our ACI fabric. Once we migrated layer 3 into the fabric, we started seeing issues where the CUBE VIP would go unresponsive for a minute or two - which takes the SIP trunk offline and drops all active calls. When the VIP was unresponsive, we didn't see any logs on the router stating that an interface was dropping.
Looking in the APIC, we saw that the VIP was attaching and detaching, constantly.
Is there a best practice configuration on the ACI side to handle a pair of routers with a VIP for HA?