On Mar 17, 2010, at 7:22 AM, Dan White wrote:
We've experienced two types of problems from time to time:
The servers stop balancing their addresses, and one server starts to exhibit 'peer holds all free leases' in its logs, in which case we need to restart the dhcpd process(es) to force a rebalance.
We experience this problem from time to time as well, and I have yet to find its cause. We also 'fix' it by restarting the dhcpd daemon.
In some cases, and I'm not sure which equipment may be to blame, if one server goes down then the other server will not hand out addresses to clients which had originally received addresses from the failed server. We've dealt with that by balancing our lease times with our MTTR for a failed server.
From the dhcpd.conf man page it seems the solution to this problem is to put the remaining active server into the PARTNER-DOWN state. Aside from the 'peer holds all free leases' error Dan mentioned, ISC DHCP's load balancing and failover has worked very well for us. -- Blake Covarrubias