KeepAlived VRID mismatch [Dropping received VRRP packet]

KeepAlived VRID mismatch

(VRID : virtual_router_id)

* 증상

 - message log에 아래 로그가 출력되기 시작함.

/var/log/message

Keepalived_vrrp[xxxx]: ip address associated with VRID not present in received packet : 192.168.17.100 Keepalived_vrrp[xxxx]: one or more VIP associated with VRID mismatch actual MASTER advert Keepalived_vrrp[xxxx]: bogus VRRP packet received on eth0 !!! Keepalived_vrrp[xxxx]: VRRP_Instance(VI_1) Dropping received VRRP packet...

* 원인

 - 동일한 VRID 를 사용하는 KeepAlived 가 존재하고 있어서 발생

   (VIP 가 다르고 VRID 가 동일한 상황)

   ex> VIP 192.168.17.100 -> VRID 20

        VIP 192.168.17.150 -> VRID 20

* 확인방법

 - KeepAlived 가 동작하는 서버에서 tcpdump 를 이용해서 vrid 확인

# tcpdump -i eth0 host 224.0.0.18 10:59:10.697847 IP 192.168.17.100 > vrrp.mcast.net: VRRPv2, Advertisement, vrid 20, prio 100, authtype simple, intvl 1s, length 20 10:59:10.698571 IP 192.168.17.150 > vrrp.mcast.net: VRRPv2, Advertisement, vrid 20, prio 100, authtype simple, intvl 1s, length 20

 - IP Multicast address 참고 [https://en.wikipedia.org/wiki/Multicast_address#IPv4]

224.0.0.18

Virtual Router Redundancy Protocol (VRRP)

* 해결방법

 - keepalived.conf 내에 vrid 값을 중복되지 않는 값으로 변경 후 KeepAlived 데몬 restart

virtual_router_id 21

출처 : http://blog.woosum.net/archives/802/