DHCPOFFER tardiness

[Jeffrey Hutzelman]

--On Friday, June 11, 2010 09:34:13 PM -0400 "Hashem, Sherif Rakhaa" 
<Sherif_Hashem at hms.harvard.edu> wrote:

>
> Sorry for the cross posting but I am ISC DHCP Server V3.1.2 and we were
> having an issue with clients taking an unusually long time receiving DHCP
> leases. On the server I realized that DHCPOFFERS are delayed. The server
> does not issue them right away. Here it took 3 minutes for the server to
> issue a DHCPOFFER.
>


> Jun 11 16:38:44 ns2 dhcpd: DHCPDISCOVER from 00:24:7e:6b:8a:19 via 
134.174.164.1
> Jun 11 16:38:45 ns2 dhcpd: DHCPOFFER on 134.174.164.238 to 
00:24:7e:6b:8a:19 (jbatista-PC) via 134.174.164.1
> Jun 11 16:38:45 ns2 dhcpd: Unable to add forward map from 
jbatista-PC.med.harvard.edu to 134.174.164.238: timed out

> In the meantime the server is handing out leases to other clients on the
> same subnet as well as to other subnets.
>
> Any ideas why this happens?

Offhand, I'm going to guess that the server is attempting a DNS update and 
the delay you are seeing is the timeout waiting to talk to the nameserver.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+ at cmu.edu>
   Carnegie Mellon University - Pittsburgh, PA