During night DHCP cluster stops serving IP addressess for LAN. The log only shows:
dhcpd: failover: link startup timeout
References:
https://lists.isc.org/pipermail/dhcp-users/2008-May/006263.html https://dhcp-users.isc.narkive.com/9MQtV2NS/frustrated-dhcp-failover-not-working https://dhcp-users.isc.narkive.com/ba1XEyJf/dhcpd-failover-link-startup-timeout https://forums.centos.org/viewtopic.php?t=54348