Core Issue
These error messages do not necessarily indicate a Hot Standby Router Protocol (HSRP) problem. Rather, the error messages usually indicate a possible Spanning Tree Protocol (STP) loop or router-switch configuration issue.
The IP address in an HSRP message received on the interface is the same as the router's own IP address. This condition may be caused by a network loop, a misconfiguration, or a malfunctioning switch.
Resolution
As a workaround, configure an Access Control List (ACL) that prevents the active router from receiving its own multicast hello packet.
HSRP packets are sent with a User Datagram Protocol (UDP) source and a destination port of 1985, so the following ACLs can be used to filter HSRP packets:
Hostname(config)#access-list 177 deny udp x.x.x.x any eq 1985
!-- x.x.x.x is the IP address of the active router.
Hostname(config)#access-list 177 permit ip any any
Apply the ACL inbound on an interface as shown:
Hostname(config)#interface ethernet 0
Hostname(config-if)#ip access-group 177 in
Refer to these documents for more information:
Other Errors, Warnings, and Log Messages
HSRP - "%STANDBY-3-DUPADDR"
