keepalived multiple instances

I have two application servers running keepalived that are both using keepalived on the same network. I keep seeing Jan 8 11:49:01 <server> Keepalived_vrrp[13764]: bogus VRRP packet received on eth0 !!! in syslog. The problem seemed to appear after I brought the second application online yesterday, is there a proper way to resolve this issue other than isolating the applications from each other?

Below is the keepalived.conf from one of the nodes on one of the app servers, they're all similar, the two different apps use different passwords but both use the same virtual_router_id.

! Configuration File for keepalived

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 2222
    }
    virtual_ipaddress {
        <public_ip>/24 dev eth0
    }
}

I was able to resolve this by adding the following to the vrrp_instance VI_1 block.

vrrp_unicast_bind 192.168.1.11   # Internal IP of this machine
vrrp_unicast_peer 192.168.1.12   # Internal IP of peer

It appears that originally that the heartbeat was going out over unicast and being picked up by the other instances. By defining the peer(s) of the machine you avoid this issue.