dhclient without arguments removes IPv4 address from loopback
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
dhcp3 (Debian) |
Fix Released
|
Unknown
|
|||
dhcp3 (Ubuntu) |
Fix Released
|
Medium
|
Scott James Remnant (Canonical) |
Bug Description
Freshly booted system (kubuntu 5.04), no dhclient run in any boot scripts:
# ifconfig lo
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:77 errors:0 dropped:0 overruns:0 frame:0
TX packets:77 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:6049 (5.9 KiB) TX bytes:6049 (5.9 KiB)
Then, run dhclient without any arguments, to look for IP on all system's
interfaces (i.e., wireless and Ethernet in my case):
# dhclient
Internet Systems Consortium DHCP Client V3.0.1
Copyright 2004 Internet Systems Consortium.
All rights reserved.
For info, please visit http://
sit0: unknown hardware address type 776
sit0: unknown hardware address type 776
Listening on LPF/sit0/
Sending on LPF/sit0/
Listening on LPF/eth0/
Sending on LPF/eth0/
Listening on LPF/lo/
Sending on LPF/lo/
Listening on LPF/eth1/
Sending on LPF/eth1/
Sending on Socket/fallback
DHCPDISCOVER on sit0 to 255.255.255.255 port 67 interval 4
DHCPREQUEST on eth1 to 255.255.255.255 port 67
DHCPACK from 131.211.80.9
bound to 131.211.80.125 -- renewal in 85282 seconds.
After which:
# ifconfig lo
lo Link encap:Local Loopback
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:78 errors:0 dropped:0 overruns:0 frame:0
TX packets:78 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:6377 (6.2 KiB) TX bytes:6377 (6.2 KiB)
and
# ifconfig sit0
sit0 Link encap:IPv6-in-IPv4
inet6 addr: ::127.0.0.1/96 Scope:Unknown
inet6 addr: ::131.211.80.125/96 Scope:Compat
UP RUNNING NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:2 dropped:0 overruns:0 carrier:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
and
# ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
--- 127.0.0.1 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms
Of course, the lack of an available 127.0.0.1 address, makes essential parts of
the system stop working. In particular, printing through cups is no longer
possible, nor is reaching the cups configuration daemon. For programs that fire
up a local webserver to offer "online" help, such as Eclipse, the help browsers
just hang, etc.
I fail to see the reason why dhclient should mess with lo in the first place.
It's rather unlikely that there will ever be any IP address handed out via DHCP
to that interface.
Changed in dhcp3 (Debian): | |
status: | New → Fix Released |
Message-ID: <email address hidden>
Date: Thu, 15 Jun 2000 23:08:20 +0200
From: Uwe Storbeck <email address hidden>
To: <email address hidden>
Subject: dhclient-2.2.x tries to get a lease for the loopback interface
Package: dhcp-client
Version: 2.0-3
dhclient-2.2.x tries to get a lease for the loopback interface "lo"!?
Interfaces for which dhclient tries to get a lease are configurable, but d/dhcp- client file,
only on the commandline. I haven=B4t found any config option in
/etc/dhclient.conf. So I=B4ve hacked the /etc/init.
but that=B4s probably not Debian policy ;-).
Debian 2.2
Linux knus 2.2.15 #1 Thu Jun 1 10:47:16 EST 2000 i486 unknown
--=20
Uwe Storbeck <email address hidden>