Re: dhclient can't get a DHCP lease..

On Mon, Feb 02, 2004 at 11:00:12AM +1030, Daniel O'Connor wrote:
> Feb  2 10:22:40 metatron dhcpd: DHCPREQUEST for 0.0.0.0 from 00:20:e0:65:13:1d 
> via dc0: unknown lease 0.0.0.0.
> Feb  2 10:22:53 metatron dhcpd: DHCPREQUEST for 0.0.0.0 from 00:20:e0:65:13:1d 
> via dc0: unknown lease 0.0.0.0.

it would have been nice to have gotten a before-n-after on
/var/db/dhclient.leases.  my only guess would be that yours was
somehow corrupted.

> DHCP server is FreeBSD with isc-dhcp3-3.0.1.r9 which hasn't changed for a 
> while.

just a side-note...if you had 'authoritative;' configured, it would send
a NAK upon the first REQ for an unknown address.  this would send clients
back to init state much more rapidly than your experience.

sadly, so rapidly you probably never would have noticed a problem.

> Gah..
> I just went to do some more tracing and it worked fine after not working
> all morning.. The working one did a DHCPDISCOVER first, though I don't know 
> why :(

my guess would be that after reaching the request timeout, dhclient entered
the address-selection loop (in dhclient's case, it picks the first one that
got ACK'd on the list and throws out all else), and since that NULL address
was the only lease and wasn't ACK'd, it exited the loop without picking a
lease.

when that happens, dhclient goes back to init state to get new leases.

if 'all morning' was an extended period, then i presume  you were
interrupting dhclient when you realized it was not working right, or
have configured a large reboot timeout in etc/dhclient.conf.

the default reboot timeout is 10 seconds.

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