hello,
I've two globally dispersed DHCP 2012r2 servers providing ip addressing service for multiple remote offices.
We have multiple failover relationship configured between those servers. Each failover relationship is configured for pool of subnets belonging to a remote site. All failover relationships are configured in hot-standby mode with automatic state switchover enabled.
Recently we've started seeing odd behaviors where only some of failover relationships would turn into "communication interrupted" and then "partner down" state. At that time communication between dhcp servers was ok and rest of failover relationships were in "normal" state.
To resolve this we had to restart dhcp service on both DHCP servers.
Until dhcp service was restarted, we got reports about duplicate ip addresses being allocated to users. While i understand that duplicate ip's might've been given by both dhcp servers due to split brain scenario (both dhcp were up, but had "partner down" state), i don't understand why duplicates were given since both dhcp servers are configured for "conflict detection attempts".
Any idea what are possible reasons that only some failover relationships fail ?
Any idea why duplicate ip's might have been allocated despite "conflict detection attempts" set (no firewall in between) ?
thank you in advance!