It has been discovered that some network drivers are not correctly
sending the routing messages (RTM_IFINFO) expected when link status
changes. These messages are used by dhclient to react properly to
such link status changes, even more so in upcoming diffs.

The diff below, which you are free to test, 'fixes' bge(4).

It would be helpful to discover which drivers are currently
misbehaving, if any other than bge do. Testing your network
card/driver is easy and fun!

As root or via sudo run

route -n monitor

and unplug and plug in your cable. You should see something like:

$ sudo route -n monitor
Password:
got message of size 144 on Fri May 9 09:06:03 2008
RTM_IFINFO: iface status change: len 144, if# 2, link: no carrier,
flags:
got message of size 144 on Fri May 9 09:06:05 2008
RTM_IFINFO: iface status change: len 144, if# 2, link: active,
flags: