In interfaces using VRRP, I’m seeing a lot of “duplicate” entries, ARP broadcasts and connectivity delays
This is what I’ve concluded in my analysis of the situation:
- Routers do their direct deliveries on the base (non VRRP) interface, using the interface MAC address in his ARP requests (even when the VRRP interface is active)
- Devices are configured (via DHCP) to use the VRRP virtual address as the default gateway and when they request the MAC of if, they get the VRRP virtual MAC
That results in:
- The routers maintain a “duplicate” ARP cache entries for each device (more processing/memory used)
- Delays in the communications every time a ARP cache entry expires, because the expected cache effect of storing the partner device IP/MAC when a request is received isn’t being effective
- More broadcasts flooding the network cause ARP cache isn’t being effective and more ARP resolutions are needed
Something should be done to solve/optimize this problem.
regards.