On CentOS 6.5, I use NM to bring up the VPN to my office, and to disconnect from it.
every now and then I screw up and disconnect the LAN itself instead of the VPN.
once I do that, even after reconnecting to the LAN I’m hosed.
/etc/resolv.conf hasn’t been put back to the non-VPN version, so I manually fix that.
but even then I can’t get any name resolution.
I’m sure that rebooting IS NOT the right answer, but it’s the only one I’ve come up with that solves the problem.
What should I be doing instead, once the system is in this state?