Re: Differences using dhcdbd and dhclient

[Dan Williams <dcbw redhat com>]

On Fri, 2007-12-07 at 12:33 +0100, Grant Williamson wrote:
> Dan,
>     I am curious what the differences are between dhcdbd and dhclient. I 
> have user in the *Philippines*, whom is trying to connect to LEAP.
> 
> The authentication part works fine from NetworkManager(wpa_cli status 
> shows it authenticated) but he never seems to be able to get a dhcp 
> lease. If I manually create a connection using a conf file and connect 
> using nm-supplicant-test then run dhclient it connects.
> 
> We are running a el5 based system, with networkmanager 0.6.5, same 
> configuration in the Netherlands or US works fine.
> 
> Does dhcdbd differ on how it requests an IP address?

There's two places here things can go wrong.

First, when starting the DHCP transaction.  dhcdbd spawns dhclient
underneath anyway.  What _might_ be different is the arguments that
dhcdbd spawns dhclient with.  But you can see that if you let dhcdbd try
to start the DHCP transaction, then do a "ps aux" and look for dhclient.
It may be that the user has custom DHCP options specified
in /etc/dhclient.conf, or custom leases specified in /var/lib/dhcp or
something, and that the straight ifup reads those files, but the
dhcdbd-invoked dhclient doesn't read the same files for initial
configuration.  Can you check to see if any of these are the case?
Other than that, there is really no difference in how stuff gets
spawned.

On the receiving end with dhcdbd, you can run 'dbus-monitor --system' to
get a dump of what dhclient sends back to dhcdbd, and then also what
states dhcdbd is in during the transaction process.  It may be that the
DHCP information isn't coming back from dhclient -> dhcdbd -> NM.  Check
that the user has the right dbus-send magic at the top of
their /sbin/dhclient-script file too.

Dan