ISC DHCP server failover

[blake at beamspeed.com (Blake Covarrubias)]

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.