keepalived — high availability with VRRP

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51        # SAME on every node in the group, unique on the L2 segment
    priority 100                # higher = preferred MASTER
    advert_int 1
    authentication { auth_type PASS; auth_pass secret }
    virtual_ipaddress { 10.0.0.10/24 }
}