Re: networkmanager gets another IP than dhclient

[Dan Williams <dcbw redhat com>]

On Fri, 2010-03-26 at 18:30 +0000, Marc Herbert wrote:
> Le 26/03/2010 17:40, Markus Feldmann a écrit :
> > Hi All,
> > 
> > i am using Debian Lenny 32bit in a local Network with a DDNS+DHCP 
> > Server. Client and Server are both Debian Lenny. My DHCP works. The 
> > clients get IP's from the DHCP server. But the networkmanager lets me 
> > get <192.168.0.196> and dhclient <192.168.0.185>. I don't know why? Has 
> > somebody any idea.
> 
> A DHCP client can request one of these two things:
> 
> - please lease me this address (again) if it still available, or
> - please lease me any address
> 
> NetworkManager requests the latter. I think a feature request has
> already been filed so NM requests the former; check the archive.

NM stored dhclient leasefiles on a per-connection basis, so that
dhclient won't try to re-request your WiFi lease when you connect to
your Ethernet network and so on (which used to happen quite a bit,
slowing down the DHCP transaction by 5 - 10 seconds or more).  Those
leasefiles are stored in the normal dhclient lease directory.  NM does
*not* use the standard single-file dhclient leasefile for the above
reason, and most distro ifup/ifdown scripts aren't smart enough to use
separate leasefiles for each distinct connection.

As of NM 0.7.1, NM will attempt to renew an existing lease, simply by
passing dhclient the leasefile and letting dhclient request a RENEW if
one of the leases in the leasefile is still valid.

dan