Incorrect arp cache entries

[andrew.keates]

We are hitting a wierd problem on Catalyst 6509s with SUP720-3BXL running VRFs and MPLS in the core with PVLANs on the access layer. We have a situation where the arp cache is showing an old mac address, which we flush with clear arp-cache interface but the entry never ages out and the server cannot ping the SVI on the Catalyst.

We are also encountering a problem with IPMP on Solaris where a failover causes the box to send a gratious ARP which is never acted upon as the arp cache still shows the failed NICs MAC address against the IP.

[vmoopeung]

This is because Stciky ARP is enabled by default.To prevent spoofing private VLAN port sticky ARP entries do not age out.Because the private VLAN port sticky ARP entries do not age out, you must manually remove private VLAN port ARP entries if a MAC address changes.

[andrew.keates]

how do you remove the arp entry given that clear arp-cache interface XXX does not work but just tries to refresh. The only way we've found of doing this is putting in a static arp entry and then removing it.