[123889] in North American Network Operators' Group
Re: ISC DHCP server failover
daemon@ATHENA.MIT.EDU (Blake Covarrubias)
Wed Mar 17 17:08:59 2010
From: Blake Covarrubias <blake@beamspeed.com>
In-Reply-To: <20100317142206.GB4773@dan.olp.net>
Date: Wed, 17 Mar 2010 14:08:24 -0700
To: "Summers, William" <wsummers@deerfield.edu>
Cc: nanog <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mar 17, 2010, at 7:22 AM, Dan White wrote:
> We've experienced two types of problems from time to time:
>=20
> 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.
>=20
> 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.
=46rom 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=
