MASTER DHCP w/ CARP not issuing IPs while SECONDARY is powered off
I have a two node CARP cluster, with three interfaces (PSYNC/CARP, WAN, and LAN). DHCP is configured for the LAN interface only. Everything was working for years until I took down the SECONDARY due to the pending arrival of Irma. As soon as I took it down I started getting DHCPDISCOVER reporting "…via hn0: not responding (startup)" in the logs. Then....
Sep 6 21:16:12 dhcpd failover peer dhcp_lan: I move from startup to communications-interrupted
On the MASTER I had the Failover Peer IP set to the static IP address of the SECONDARY LAN interface (and vice versa), and as soon as I removed that entry, the MASTER started issues IP addresses again. The desired state is that this is automatically failed over if the SECONDARY goes offline/unresponsive, but I guess I never accomplished that and no one noticed as both routers have been rock solid.
Am I missing something or is this working as designed?
Thanks in advance.
If both are up and in a 'normal' status and then one fails, the other will keep handing out addresses.
If DHCP is restarted on the primary while the secondary is offline, it can never reach a failover peering state where it believes it should be able to hand out addresses.
That makes sense. So there is no way to have the failover peer added to work during "normal" operations AND have it work during a long-term peer outage?
No, because failover is not designed to work with a long-term peer outage. Multiple things will fail (xmlrpc sync, for example)
If you will have a long outage you'll have to manually remove some of the sync settings until the peer is repaired.