How do I reset the network stack as if from a reboot?

Question

Sometimes my netbook (Dell Mini 10v with Broadcom bcm4322 wireless adapter, Ubuntu 12.04.2 LTS) gets into a state where it can see wireless connections but not connect to them.

Rebooting always fixes this, but is a pain in the neck.

Sometimes

sudo service network-manager restart

works too, but not always.

I suspect a problem somewhere in the network stack, probably driver-related, but I've no idea how to find out what it is, and the fault is too intermittent for blind debugging anyway.

Is there any way to force a reset of the entire network stack without having to do a full reboot?

Several different commands is fine. I can script.

Failing that, is there a detailed guide to working out what the problem actually is?

Solution 1

What seems to be working so far is:

sudo modprobe -r wl 
sudo modprobe wl
sudo service network-manager restart

I don't know if this is a full-stack restart, but it seems to do the trick in my case

various cryptic commands that helped in discovering this sequence were:

iwconfig
nm-tool
ip link
sudo lshw -C network
lspci
sudo service networking restart

Solution 2

I use

sudo service networking restart

This is not ideal in some cases, see also:

• How to restart the networking service?