dhclient3 not recognize -4 option sent by network manager

[smidl]

Binary package hint: dhcp3-client

This is about interaction of nentowrk-manager and dhclient3 in current maverick.

My wifi AP does not support IPv6, so the nm is trying to instruct dhclient not to use it.
And apparently fails.
Described in: http://pugio.net/2010/08/fix-dhcp-problems-in-networkmager.html

My current syslog is:

Sep 8 22:50:54 note381 kernel: [ 154.330060] wlan0: no IPv6 routers present
Sep 8 22:51:27 note381 kernel: [ 187.330684] lo: Disabled Privacy Extensions
Sep 8 22:54:55 note381 dhclient: Internet Systems Consortium DHCP Client V3.1.3
Sep 8 22:54:55 note381 dhclient: Copyright 2004-2009 Internet Systems Consortium.
Sep 8 22:54:55 note381 dhclient: All rights reserved.
Sep 8 22:54:55 note381 dhclient: For info, please visit https://www.isc.org/software/dhcp/
Sep 8 22:54:55 note381 dhclient: Usage: dhclient [-1dqrx] [-nw] [-p <port>] [-s server]
Sep 8 22:54:55 note381 dhclient: [-cf config-file] [-lf lease-file][-pf pid-file] [-e VAR=val]
Sep 8 22:54:55 note381 dhclient: [-sf script-file] [interface]

[Serge Hallyn (serge-hallyn)]

Thanks for reporting this bug and helping to make ubuntu better.

I believe this should be marked as a bug against network-manager rather
than dhcp3-client. There is a patch in network-manager which detects
the dhcp client at *compile* time and removes the -4 option, so clearly they
are aware of the issue. The question then is whether and how to detect it
at package installation or perhaps even daemon startup or runtime.

[smidl (vasek-smidl)]

Thanks for your answer Serge.

Are there any other dhcp clients available in maverick then? I though that dhcp3 is the only one. In that case, there is no need to detect it at runtime, right?

[smidl (vasek-smidl)]

Probably related to Bug #527313, the "-4" option was mentioned in one of the comments there.

However, the workarounds mentioned there do not work for me. I have to stop NM and do iwconfig and dhcpclient manually.

[Mathieu Trudel-Lapierre (cyphermox)]

smidl,

Can you please confirm which version of NM you are running? You can do this with the "dpkg -l network-manager" command.

[Mathieu Trudel-Lapierre (cyphermox)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. However, according to this report, you are not using the most recent version of this package for your Ubuntu release. Please upgrade to the most recent version and let us know if you are still having this issue. Thanks in advance.

[smidl (vasek-smidl)]

I can confirm that the message "Usage: dhcp..." is no longer appearing in logs.

With the latest package
network-manager 0.8.1+git.20100810t184654.ab580f4-0ubun
It is replaced by time out:
Sep 20 20:06:15 note381 NetworkManager[991]: <info> (wlan0): DHCPv4 state changed nbi -> preinit
Sep 20 20:06:16 note381 dhclient: Listening on LPF/wlan0/00:22:fb:18:11:3a
Sep 20 20:06:16 note381 dhclient: Sending on LPF/wlan0/00:22:fb:18:11:3a
Sep 20 20:06:16 note381 dhclient: Sending on Socket/fallback
Sep 20 20:06:16 note381 dhclient: DHCPREQUEST of 192.168.2.51 on wlan0 to 255.255.255.255 port 67
Sep 20 20:06:30 note381 dhclient: last message repeated 2 times
Sep 20 20:06:30 note381 dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 3
Sep 20 20:06:33 note381 dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 4
Sep 20 20:06:37 note381 dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 10
Sep 20 20:06:47 note381 dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 16
Sep 20 20:07:01 note381 NetworkManager[991]: <warn> (wlan0): DHCPv4 request timed out.
Sep 20 20:07:01 note381 NetworkManager[991]: <info> (wlan0): canceled DHCP transaction, DHCP client pid 20840

Manual setup via "iwconfig essid my_essid" "dhcp wlan0" still works without any problem.
Should I file another bug report?