sudo: unable to resolve host dhcppc0

Now this is a weird problem. I assume dhcp client sets this "dhcppc0" address in cases where hostname is bad, missing or similar. I don't see this with my two laptops, but I'm guessing this is somehow related to the dhcp server.

I'll find from the code where this dhcppc0 hostname is set, but in the mean time I have few questions which would help to reproduce the problem:

* what dhcp client are you using, the default from lucid? dpkg -l '*dhcp*' helps here
* what kind of network setup? ethernet, wifi? anything special?
* what's the dhcp server? usually it's in the wireless router
* what is the original hostname (before dhcppc0 is set)?

I am using Maverick but before upgrade the problem was there too.

1. dhcp client is the default version.
2. I am using wifi.
3. see screenshot
4. it was om26er-netbook

I checked the dhcp client sources (dhcp-client 3.1.3-2ubuntu3) and I didn't find anything related to setting dhcppc0 (or similar) hostname. So I suspect dhcp server provides the hostname in the dhcp offer and connman currently sets that as the hostname without any checks of whatsoever.

I think this part needs improvement. In some cases it makes sense to change the hostname, but in most of cases the hostname should not be changed at all. Also the fact that connman does not set the search list in resolv.conf might affect here.

I created a test package of connman which does not set the hostname at all:

https://launchpad.net/~kvalo/+archive/ppa/+files/connman_0.53+dfsg-0ubuntu0.10.04.1~ind1~bug586794-1_amd64.deb
https://launchpad.net/~kvalo/+archive/ppa/+files/connman_0.53+dfsg-0ubuntu0.10.04.1~ind1~bug586794-1_i386.deb

Please test and provide feedback.

Kalle,

That .deb package of connman fixed the issue for me.

Fixed

Cool, thank you both of you for very quick tests!

So it's now obvious that a quick fix is just to ignore the hostname from dhcp. Longer term fix might be to set hostname only in very special cases, but that needs a lot more thought and is still risky. If someone has opinions or use cases for using the hostname from dhcp offers, I would gladly hear about them.

This bug was fixed in the package connman - 0.54+dfsg-0ubuntu1

---------------
connman (0.54+dfsg-0ubuntu1) maverick; urgency=low

  * New upstream version
  * debian/patches/0001-dhcp-don-t-set-hostname.patch:
    - change by Kalle Valo to not set dhcp hostname (lp: #586794)

  [ Mathieu Trudel ]
  * update get-orig-source/GET_SOURCE code snippets to deal with dfsg,
    as well as alternate branches.
    - update debian/rules

  [ Chris Coulson ]
  * Add patch from Kalle Valo to set default interface if no gateway is found
    - add debian/patches/02-set-default-interface-if-no-ga.patch
    - update debian/patches/series
  * Build with --enable-ofono and drop --enable-hso
    - update debian/rules
 -- Sebastien Bacher <email address hidden> Mon, 28 Jun 2010 17:52:05 +0200