Description of problem: Switching away from a system connection appears to blow away the DNS entries associated with that connection. Version-Release number of selected component (if applicable): 0.7.0.99-5.git20090326.fc10 How reproducible: Consistently. Steps to Reproduce: 1. Start system-config-network and ensure there are entries present for DNS. Close it. 2. Switch away from, then back to a "system" connection in NetworkManager. 3. Restart system-config-network and switch to the "DNS" tab. The entries should now be empty.
That's because system-config-network writes entries directly to /etc/resolv.conf. Unfortunately, DNS information comes from multiple places and that all needs to be concatenated into /etc/resolv.conf at the time the connection is made. When connected to a VPN or PPP, which are both transient connections, you certainly want your VPN/PPP DNS servers in /etc/resolv.conf, but you also certainly don't want them there *all the time*. To achieve the right behavior, you probably want to add specific DNS servers to your ifcfg files (which get written by system-config-network) in /etc/sysconfig/network-scripts/. Add DNS1=x.x.x.x and DNS2=y.y.y.y for example. Then NetworkManager will do the right thing.