Users report that traffic is negatively affected every time a BIG-IP device fails over.

When traffic "stabilizes after a few minutes" following a failover, it points to a network-level performance issue involving ARP cache on upstream routers and switches. Each BIG-IP interface has a unique hardware MAC address. During failover, the Standby device takes over the floating IP address, but the upstream switch still associates that IP with the MAC of the now-offline device. Traffic is lost until the switch learns the new MAC or its ARP entry expires. "MAC Masquerading" solves this by creating a shared, virtual MAC address for the floating traffic group. This virtual MAC is used by whichever device is currently active. Because the MAC address for the virtual server IP never changes from the perspective of the network, the upstream devices do not need to update their ARP tables. This troubleshooting solution eliminates the delay associated with failover, providing a seamless transition and ensuring that application traffic flow is not disrupted when the BIG-IP HA state changes.