I haven't got all the details as yet, but a customer is saying that if he uses a certaing HSRP group number (say for argument number 16) he has intermittent IP connectivity - i.e. Intermittent Ping Packet drops. If he just changes the group number to any any other number - 64 for example there is no problem at all. No IP packet drops at all.
Is it possible that Group Number of 16 which translates to a MAC Address of 00-00-0c-07-ac-10 may have an "Evil Twin" MAC address in their network, but if he uses another group number it will translate to another MAC address and hence has no problem?
I told him to not configure the problem group number 16 and look at the CAM table of his two CAT 6500 and see if there is a MAC address of 00-00-0c-07-ac-10. If there is then we know we have an "Evil Twin" - Inglebert.