Dear All,

This is regarding the occasional packet drops we are facing in HSRP IP of (in a specific VLAN) our core switches (Cisco 6509). The scenario is explained below:

We have a VLan for Voice devices (IP Phones) with a HSRP IP. We have been observing some occasional packet drops on this IP (while we can see no drops on HSRP IP for the other VLan which has been configured on the same pair of switch).

The problem of packet drop is reported by a ICMP based tool ( Ping Plotter) running on that VLAN (100) as of now the logs on the switch don't exhibit any log relevant to this problem.

We have also tried running Ping Plotter on some other VLan ( VLan 110) pointing a different HSRP IP configured on the same pair of switches.. when we see drops on HSRP IP of VLAN 100.. during the same time the Ping Plotter working on VLan 110 reported no packet drops!

I have also observed that sometime the blip in MPLS also results in packet drop in the HSRP IP.. but I feel.. that any blip in WAN side shouldn't cause packet drop in this LAN IP.

I would seek your imperative advices on this subject!

Note: I have attached copy of Show Tech-Support for both of the 6509 with this conversation.

Thanks and Regard,

Mayank