We pick e.root-servers.net, one of the 13 root servers (1), and ask it about a.u-psud.fr and learn that fr is delegated to five name servers (2), so we ask d.ext.nic.fr where we learn that u-psud.fr is delegated to four name servers, including ext1.u-psud.fr (3), so we ask that one and get the following answer:
A.u-psud.fr is a domain controlled by three domain name servers at u-psud.fr having a total of five IP numbers. Some of them are on the same IP network. Incoming mail for a.u-psud.fr is handled by two mail servers also at u-psud.fr. Both are on the same IP network. A.u-psud.fr has one IP number (129.175.33.40), which is the same as for u-psud.fr, but the reverse is smtp.u-psud.fr.
Most of them use the name server ext1.u-psud.fr. Worth noting is that half of the domains that use the name server ext1.u-psud.fr point to the IP number 129.175.33.40.
Most of them use the name server dns2.u-psud.fr. Worth noting is that a third of the domains that use the name server dns2.u-psud.fr point to the IP number 129.175.33.40.
The name server ext1.u-psud.fr
There are about fifty domains that use the name server ext1.u-psud.fr.
Half of them point to the IP number 129.175.33.40. Worth noting is that most of the host names that point to the IP number 129.175.33.40 use the name server ext1.u-psud.fr.
The IP number 129.175.33.40 only
Most of the about thirty host names that point only to the IP number 129.175.33.40 use the two mail servers smtp1 and smtp2.u-psud.fr together, hereafter referred to as "mail server group 1". Worth noting is that a third of the domains that use mail server group 1 point only to the IP number 129.175.33.40.
The name server dns2.u-psud.fr
There are about sixty domains that use the name server dns2.u-psud.fr.
