Be it the home computer, the friend’s wi-fi or the personal VPS, in some instances using the ISP’s DNS service is not desirable. Maybe for speed or maybe for privacy concerns a trusted DNS provider is preferred instead.
While the DNS settings can be manually changed after each (re)connection, applying a permanent solution requires a bit of file fiddling.
Create /etc/dhclient-enter-hooks with the following contents:
echo "doing nothing to resolv.conf"
Change its permissions to make it executable:
chmod a+x /etc/dhclient-enter-hooks
See man dhclient-script for more info.
Edit etc/sysconfig/network-scripts/ifcfg-eth0 (or whichever your network interface file is) and add
Remember to use the DNS server IP addresses appropriate for your network.