Broadband DNS lookup error, stuck on 'resolving host'

One activity of the Shrewsoft VPN, ike is to edit the /etc/resolv.conf, changing the nameserver from those provided by an ISP.

After a system crash (in my case Cinnamon freezing) this file doesn't seem to 'unload' in some way (i.e. edited back the way it was found), so nameserver was not reset to the network nameserver - without a VPN connection therefore the connection could not be made other than to the router management page.

Most broadband ISPs "don't support Linux", so try DNS resolution troubleshooting guides for further help.