VRRP/HSRP and auto last hop tunning - why necessary?

Hi Piotr,

yes your assumption 2 is not correct. HSRP e.g. uses it's physical router MAC as source not the virtual MAC associated with the VIP. It gets even worse when using Cisco's vPC. In this case you will see all physical MACs as source depending which physical device forwards the packet. They behave like active/active for sending packets regardless which one is active for the group an owns the VIP.

IMHO the default setting using auto last hop is kind of dangereous as it is not compatible with HSRP, VRRP, ClusterXL which are used in many environments. Why not just use the routing table which will allways forward return traffic to the VIPs MAC? It's not as smart but won't lead to problems where admins don't know the details about redundancy protocols...

Cheers

Alex