Comment 32 for bug 90681

"I suppose some people might have problems if their VPN solution completely replaces /etc/resolv.conf. That might require a more sophisticated solution"

This is the case for me. My resolv.conf gets replaced whenever I connect to my vpn. This is to avoid doing dns resolution on an untrusted network (e.g., free wifi at coffee shop). Also in cases where the network I'm on is sandboxed, such as the wireless segment of my lan, there is limited DNS resolution available. In this case, full dns resolution must be done at the trusted end of the tunnel.

When the dhcp renewal blows away my "trusted" resolv.conf, then the result is either that DNS resolution moves to the untrusted network, or DNS resolution breaks because resolv.conf now points to the sandbox DNS address.