> On 9/7/06, Eric Shubes <plug@shubes.net> wrote:

> > On FC5, $HOSTNAME appears to be set in /etc/rc.d/rc.sysinit.
> > Of course, rc.d and rc.sysinit don't appear to exist on ubuntu.

From the Ubuntu Policy Manual:
9.3.4 Boot-time initialization

There used to be another directory, /etc/rc.boot, which contained scripts which were run once per machine boot. This has been deprecated in favour of links from /etc/rcS.d to files in /etc/init.d as described in Introduction, Section 9.3.1. Packages must not place files in /etc/rc.boot.

/etc/rcS.d/S02hostname@ sets HOSTNAME to the contents of /etc/hostname (very short description) and S40networking@ uses /sbin/ifup -a to initialize the network interfaces according to /etc/network/interfaces which (on this system) contains:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# This is a list of hotpluggable network interfaces.
# They will be activated automatically by the hotplug subsystem.
auto eth0

# The primary network interface
iface eth0 inet dhcp

Which makes it look like ifup is the one invoking dhclient for eth0.  Unfortunately ifup is a binary so I have no way of knowing why it does not seem to use the available hostname in making the call to the DHCP server.  I think I am dead-ended here as there is no way I am going to dig through source code trying to find this answer. 

Perhaps someone more qualified than me could be interested in the question.  I really do believe this is a bug and ought to be pursued even if it would not be important to a lot of folks.

> > I can't find anywhere on ubuntu that HOSTNAME is set, except in
> > /etc/pcmcia/network and /etc/pcmcia/network.conf, which shouldn't come into
> > play (I wouldn't think) with a PCI NIC card.
> >
> > I'll go now, seeing as I'm pretty much useless regarding this problem.
> > --
> > -Eric 'shubes'
> > ---------------------------------------------------

--
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.  - Dr. Seuss