Failover and duplicate DHCPACKs

[David W. Hankins]

On Sat, Feb 20, 2010 at 09:32:27AM +1100, Glenn Satchell wrote:
> Looking at the log files in the first case with failover, the client
> goes through the discover/offer/request/ack cycle. 30 minutes later
> (half the lease time) it renesw using a request/ack. Then at the 60
> minute mark it goes through a discover/.. cycle again. The odd thing
> is that the renewals are going via the dhcp relay - renewals are
> unicast so they should go directly from the client to the dhcp
> server.

Just an idea - if the servers are getting the renewals via the
relay (or rebinding for that matter) it could be that one of the
servers on the relay agent's forward list doesn't have a consistent
idea of the network(s) that are appropriate for that relay agent's
giaddr...

So the client could be getting a DHCPNAK from some server (maybe an
old one you migrated away from ages ago?), and that will also cause it
to go back to DHCPDISCOVER more or less right away.

-- 
David W. Hankins	"If you don't do it right the first time,
Software Engineer		     you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins
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