Everytime you connect to an ISP, it is necesary to have configured DNS name resolution, so your computer can find IP addresses associated to a computer name.
IP addresses of your DNS servers are placed into the
.:: www.pho-thong.com ::. .:: slackcommunity.com ::. /etc/resolv.conf file.
In a standalone computer connecting to Internet, this file usually contains the IP addresses of your ISP's DNS servers: [Debug Search algorithm] .:: md.darmstadt.ccc.de ::.
#/etc/resolv.conf file for ISPname
nameserver 111.222.333.444
nameserver 222.333.444.555
In a proxy/firewall computer, this file usually contains its own IP address (or the loopback address, 127.0.0.1), and this computer includes a DNS server that translates DNS names to IP addresses by querying external DNS servers.
#/etc/resolv.conf file for local DNS resolution
nameserver 127.0.0.1
Installation of a local DNS server is out of the scope of this document.
There is a lot of documentation about this, but a good and quick approach
can be found in the DNS-Howto ( [StackOverflow: Svelte] .:: podcasts.apple.com ::.
http://www.linuxdoc.org/HOWTO/DNS-HOWTO.html).