NETWORKING=yes HOSTNAME=totosh.ampoliros.net GATEWAY=192.168.0.254
# DNS FDN nameserver 22.214.171.124 nameserver 126.96.36.199
This is about associating and IP address with a domain name. It usually depends on your access provider, since they provide you with an IP address.
My internet access provider for totosh is currently Free SAS. The reverse DNS setup is described at http://www.free.fr/assistance/248.html.
To check the rDNS:
$ host 188.8.131.52 184.108.40.206.in-addr.arpa domain name pointer totosh.ampoliros.net.