Domain Delegation

This document contains an example of what to do in the BIND config file and the zone file to cause domains to be delegated.

The example uses the Arizona.EDU delegating nameservice for Philosophy.Arizona.EDU and 23.196.128.IN-ADDR.ARPA to Socrates.Philosophy.Arizona.EDU (128.196.23.5). (See the sample configuration file for additional information about this example.)

It is not necessary to change the BIND config file on the rootward name server when it delegates a subdomain. A sound standard procedure, however, would be to have the primary (main) name server (Arizona.EDU in this example) act as a secondary for all of its subdomains. To do this, you would add lines like the following to the BIND config file:

  secondary Philosophy.Arizona.EDU  128.196.23.5 Philosophy.Dump
  secondary 23.196.128.IN-ADDR.ARPA 128.196.23.5 Philosophy-Subnet.Dump

zone "Philosophy.Arizona.EDU" in {
  type slave;
  masters { 128.196.23.5; };
  file "MULTINET:Philosophy.Dump";
};

zone "23.196.128.IN-ADDR.ARPA" in {
  type slave;
  masters { 128.196.23.5; };
  file "MULTINET:Philosophy-Subnet.Dump";
};
 

          

The important part of the domain delegation is for the superior zone file to have the proper NS record pointing to the primary name server for the subdomain.

The zone file for Arizona.EDU (multinet_dns:arizona.hosts on Arizona.EDU) contains:

  $ORIGIN Philosophy.Arizona.EDU.
  @    IN   NS       Socrates.Philosophy.Arizona.EDU.
       IN   NS       Arizona.EDU.     ; include ourselves too
  Socrates IN   A    128.196.23.5     ; "glue" record

          

The zone file for 196.128.IN-ADDR.ARPA (multinet_dns:univ-ariz.rev on Arizona.EDU) contains:

  $ORIGIN 23.196.128.IN-ADDR.ARPA.
  @    IN         NS     Socrates.Philosophy.Arizona.EDU.
       IN         NS     Arizona.EDU.
  ; no "glue" needed.

          

Restart the name server, and the change is complete.

Note: The subdomain's name server should set up its zone files and set up itself as primary, and test this configuration, before the rootward name server makes the delegation.