It works the same as any other corporate network: either custom DNS resolution on the machine (i.e. /etc/hosts), DNS resolution in the internal network, or DNS

It works the same as any other corporate network: either custom DNS resolution on the machine (i.e. /etc/hosts), DNS resolution in the internal network, or DNS resolution on the VPN. Or, more likely, a mix of the 3. To get to go links, you've got to be connected to Google's network (either physically, or through VPN). It's essentially the same as accessing a computer on your LAN with its host name (in which case, the router can do the DNS lookup and resolution for the internal network).