I have connected my girlfriend's laptop to a university network (in halls/dorms) and have had to make some manual changes to /etc/network/interfaces (for static IP purposes) and /etc/resolv.conf (to enter DNS server info). Everything was working great with these settings, but after leaving her room, accessing wireless in the library, and then returning to her hardwired connection, her internet no longer works.

When I went back to the resolv.conf file, I found that all of my changes were deleted and replaced with something to the effect of 'Settings managed by Network Manager'. It appears that Network Manager is overwriting the settings I made in resolv.conf. Re-entering this information solves the problem, but I would not expect my girlfriend to have to do this every time she wants to access the internet.

The computer must be on a static IP when connected via cable, as it needs to connect to the university's DNS servers. I don't believe uninstalling Network Manager is the way forward, because I worry that my g/f won't be able to easily switch between wireless and hardwired as the need arises.

Does anyone know how to resolve this issue? How can I keep my resolv.conf file from being overwritten regularly by Network Manager? I read somewhere that entering 'ifdown eth0' in Terminal, making the changes to the resolv.conf file and then going back into Terminal and entering 'ifup eth0', the problem can be solved. Has anyone else had any luck with this. Any help would be greatly appreciated.