[TriLUG] dhclient with Debian not picking up address

[Corey Mutter]

I cn confirm this.

> The same thing happened for me when I recompiled my kernel -
> unfortunately I went through this awhile back. Here are some things I
> highlighted in my notes that you may want to check:
>
> make menuconfig
>     Networking options - the following have to be checked for DHCP use
>        Packet socket
>        Packet socket: mmapped IO
>        Socket Filtering

Those are the key (packet socket and socket filtering), as the DHCP
client needs to send "raw" packets (it can't just use a UDP socket,
because then it will have the bug one of my products does, that the
kernel will fill in the source IP instead of leaving it 0.0.0.0).

>
>     Network device support - make sure you have the correct network card
>        3c590/3c900 series (592/595/597) Vortex/Boomerang suuport
>        (this selection is for my network card - 3c905B)

This is already OK in your kernel, because the interface works OK for
you if manually configured.

>
> I hope this helps or at least someone else might chime in once they get
> to work and wake up :)
>
> Lisa B.
>
> bdsmith at nc.rr.com wrote:
> > I recently installed Debian 3.0, install went without a hitch, and
> > dhclient picked up all the necessary information from the DHCP
> > server. After recompiling the kernel, however, dhclient quit working
> > (it runs, but fails to configure the ethernet interface, and gives me
> > no error message). I made sure to compile DHCP support into the
> > kernel (Networking options ---> TCP/IP networking ---> IP:kernel
> > level autoconfiguration ---> IP: DHCP Support), but to no avail. I
> > can manually configure the interface using ifconfig and route, and
> > everything works fine. Is there something in the kernel I'm missing,
> > does dhclient not work with the 2.4.20 kernel (the install program
> > used the 2.2.20 kernel)?

You do not need "kernel level autoconfiguration" to use DHCP. That
option will build a DHCP lcient into the kernel, but is only needed
for diskless workstations (they need to get onto the network to
NFS-mount their root filesystems, and so needs to configure the network
in the kernel before "init" is run, rather than configuring the
network in the bootup scripts as typical systems do).

Corey