failover with active / standby configuration

[Glenn Satchell]

>Date: Mon, 2 Mar 2009 17:37:24 +0000
>Subject: failover with active / standby configuration
>From: Daniel Duarte <dan.r.duarte at gmail.com>
>To: dhcp-users at lists.isc.org
>X-BeenThere: dhcp-users at lists.isc.org
>
> Hello,
> 
> I would like to use the failover protocol, on an active / standby way. One
> of the servers would be "master", and the other "slave". The slave would
> just be waiting for the master to fail, to take control.
> 
> I've seen some posts related to this. I believe I could accomplish it by
> setting the split option to 0 or 256, but I haven't found a clear answer to
> this question:
> 
> 1. If the two servers split the pools between them, when I configure 0 or
> 255, would all the IP addresses of the pools be allocated to only one
> server? If so, when the first server dies, does the slave have free IP
> address of its own to allocate to new clients?
> 
> 2. Is there any known disadvantage with this configuration? I'm using
> version 3.0.1.
> 
> Thanks,
> Daniel Duarte

You definitely need to upgrade from 3.0.1. There have been heaps of
bugs and enhancements for failover since then. I would suggest either
the latest 3.1.x or 4.1.x release. Both of these should work unchanged
with your current config files, although you may need to add
"authoritative;" in the global scope as the default changed somewhere
about 3.0.4 or 5.

regards,
-glenn