Which configuration would resolve an ARP issue after an HA failover in a NetScaler active-passive pair?

• A. Independent Network Configuration (INC) mode
• B. Virtual MAC
• C. HA monitor
• D. Route Monitor

Answer: (B)

In an active-passive Citrix ADC pair, the VIP must stay reachable even if the primary unit fails. ARP caches on upstream devices map the VIP to a MAC address, and if failover causes the MAC to change, those caches may hold the old mapping and traffic can be disrupted. Using a virtual MAC means the VIP is always advertised with the same MAC address, regardless of which unit is active. When failover happens, the new active unit answers ARP with the same virtual MAC, so upstream devices and clients continue sending frames to the same MAC and traffic remains seamless. This prevents ARP churn and blackholes after failover. The other options don’t address this MAC-level continuity: independent network configuration mode deals with network segmentation, HA monitor checks service health, and route monitor tracks routing changes, but none fixes the ARP stability that VMAC provides.