Keepalived

Refs

• https://github.com/acassen/keepalived/blob/master/keepalived/etc/keepalived/keepalived.conf.in-
• https://nutss.wordpress.com/2019/07/12/high-availability-support-keepalived-and-nginx-on-ubuntu-debian/
• https://askubuntu.com/questions/1312333/keepalived-not-working-on-20-04

apt update && apt install keepalived
sudo useradd -r -s /bin/false keepalived_script

/etc/keepalived/keepalived.conf

global_defs {
   notification_email {
     myuser@example.com
     failover@example.com
     sysadmin@example.com
   }
   # notification_email_from Alexandre.Cassen@example.com
   # smtp_server 192.168.200.1
   # smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.200.16
        192.168.200.17
        192.168.200.18
    }
}

Logs

systemctl status keepalived
journalctl -f

capture multicast traffic

sudo tcpdump -npi eth0 net 224
16:10:05.472897 IP 172.16.0.167 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 100, authtype none, intvl 1s, length 28

```