We pick h.root-servers.net, one of the 13 root servers (1), and ask it about hysing.is and learn that is is delegated to seven name servers (2), so we ask is.cctld.authdns.ripe.net where we learn that hysing.is is delegated to three name servers, including c.hysing.is (3), so we ask that one and get the following answer:
Hysing.is is a domain controlled by three domain name servers at hysing.is themselves. Two of them are on the same IP network. Incoming mail for hysing.is is handled by two mail servers also at hysing.is. Both are on the same IP network. Hysing.is has one IP number (193.4.129.129), but the reverse is hmsweb4.hysing.is.
Twelve of them use the name server c.hysing.is. Worth noting is that twelve of the domains that use the name server c.hysing.is point to the IP number 193.4.129.129.
Twelve of them use the name server b.hysing.is. Worth noting is that twelve of the domains that use the name server b.hysing.is point to the IP number 193.4.129.129.
The mail server mxa.hysing.is
There are several hundred of domains that use the mail server mxa.hysing.is.
Six of the about twenty host names that point only to the IP number 193.4.129.129 use the two mail servers mxa and mxb.hysing.is together (but not mx.hysing.is ), hereafter referred to as "mail server group 2". Worth noting is that six of the domains that use mail server group 2 point only to the IP number 193.4.129.129.
The three mail servers mx, mxa and mxb.hysing.is together
There are more than two hundred domains that use mail server group 1.
There are several hundred of domains that use the name server b.hysing.is.
Five percent of those point to the IP number 193.4.129.129. Worth noting is that twelve of the host names that point to the IP number 193.4.129.129 use the name server b.hysing.is.
