Routing table troubles with vpnc on Debian

Question

I am trying to use vpnc to wirelessly connect to a VPN network on Debian Wheezy (testing). Making sure that wlan0 is up, I am able to establish a connection and maintain it for a minute or two. During this time, route shows a default destination bound to tun0. Trouble is that soon enough another default entry will crop up, pointing to wlan0. As far as I can tell, the vpnc prefers tun0, but wlan0 precedes it in the routing table. The VPN client itself seems to handle stuff correctly, but is then surprised by something dynamic happening. How can I stop wlan0 from hijacking the default entry in the routing table?

Similarly, I would like to be able to permanently send network interfaces down. However, as often as I do ifconfig eth0 down, it will always come up again after a few minutes. The same goes for wlan0, which usually is accompanied by wlan0:avahi. What are daemons that would do this kind of mischief? How do I turn them off to gain full control over my network interfaces?

Cheers.

Answer 1

Right, I think I got it. I installed wicd a while ago, which manages network interfaces and overrides ifconfig and friends. If inexplicable things happen in a daemonised way on your machine, have a look at /etc/init.d, e.g. grep all files in it like so:

grep 'Short-Description' /etc/init.d/*

Then use update-rc.d or rcconf to remove the daemon or uninstall the corresponding package, as I did with wicd. Done!