Nameserver Requirements

Nameservers hosting Icelandic domains (.IS domains) must comply with all of the following requirements:

1. Nameservers must allow connection to UDP port 53, and to TCP port 53 as well (see RFC5966).
2. Nameserver must be consistently registered in DNS, i.e. its own A resource record must be available and a corresponding PTR resource record as well.
3. Namesever name can only contain ascii letters, digits, hyphen and periods.
4. For nameservers within the .IS zone, the following also applies:
1. Hostname can not be numeric only (i.e. 123.isnic.is) (See: RFC1035 RFC1123 RFC1912 ).
2. The full name of the nameserver (FQN) must include the hostname (i.e. the canonical name of the machine the nameserver is running on).