Re: DHCP lease being renewed every 30 seconds!

[Sebastian Tennant <sebyte@smolny.plus.com>]

Nate Bargmann wrote:
> * Sebastian Tennant <sebyte@smolny.plus.com> [2005 Oct 26 16:53 -0500]:
> 
>>Hi all,
>>
>>I'm running Debian GNU/Linux on an i686 platform.  I've recently
>>reinstalled from scratch and have since noticed that my DHCP lease
>>(correct terminology?) is being renewed every 30 seconds, causing the
>>following three lines to be written to my syslog every 30 seconds.
>>This was never the case before.
>>
>>  Oct 25 23:58:08 localhost dhclient: DHCPREQUEST on eth0 to 192.168.1.1 port 67
>>  Oct 25 23:58:08 localhost dhclient: DHCPACK from 192.168.1.1
>>  Oct 25 23:58:08 localhost dhclient: bound to 82.155.151.120 -- renewal in 30
>>seconds.
>>
>>Is this behaviour normal?  If so, what could have changed?  My ADSL
>>internet connection appears to be functioning normally.  How can I
>>configure dhclient or syslog not to record this level of information?
>>
>>Yours with very little clue about DHCP and leases,
> 
> 
> No, this is not normal.  Lease times are generally set by the DHCP
> server as I understand it.  However, you may want to check
> /etc/dhclient.conf to be sure something isn't in there.  Mine is
> completely commented out and that is the default since I never modified
> the file.You might want the move /var/lib/dhcp/dhclient.leases to some
> other location as dhclient will cache leases to this file per the man
> page.  It could be picking up erroneous information from it.
> 
> I just looked at my logs and I have a DHCPREQUEST entry several times
> and repeated at non-obvious intervals.  I'm going to wath the box with
> Ethereal and see what's going on.  Maybe there is a buggy dhcpclient on
> the loose?
> 
> - Nate >>

My /etc/dhclient.conf was entirely commented out too but I noticed these lines and
thought that I might as well try rebooting with 'send dhcp-lease-time 3600' uncommented:

  # Normally, if the DHCP server provides reasonable information and does
  # not leave anything out (like the domain name, for example), then
  # few changes must be made to this file, if any.

  #send host-name "andare.fugue.com";
  #send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
  send dhcp-lease-time 3600;

Unfortunately, it's made no difference.

Someone on the ISC dhcp-dhclient mailing list has suggested dhcpdump to see what's going
on. He thinks it might be my ADSL provider.  I'm working abroad, so my ADSL provider is
one thing that has definitely changed.  In fact, so has my modem for that matter.  I
suppose it could be the modem too.   Hmmm...  Not so straightforward as I had hoped :-/

sebyte