Setting Up a Subdomain

In most cases, new subdomains are usually created from the start with a new network and machines, or split off from an existing domain. The process is essentially similar in both cases.

Once you have planned your new subdomain, follow these steps to set it up:

1. Make sure all of the machines in the new subdomain are properly set up as DNS clients.

   If you are carving a new subdomain out of an existing domain, most of the machines are probably already set up of DNS clients. If you are building a new subdomain from scratch (or adding new machines to an existing network) you must install properly configured resolv.conf and nsswitch.conf files on each machine as described in Solaris Naming Setup and Configuration Guide.

2. Install properly configured boot and DNS data files on the subdomain's primary master server.

   Install the following files on each server (see Solaris Naming Setup and Configuration Guide for details):

   • /etc/named.boot.

   • /var/named/named.ca.

   • /var/named/hosts.

   • /var/named/hosts.rev.

   • /var/named/named.local.

   Note that the server host files must have an Address (A) record, any necessary CNAME records for each machine in the subdomain and the server hosts.rev files must have a pointer (PTR) record for each machine in the subdomain. Optional HINFO and WKS records can also be added.

3. If you are splitting an existing domain, remove the records for the machines in the new subdomain from the parent domain's master server hosts and hosts.rev files.

   This requires deleting the A records for the machines that are now in the new subdomain from the hosts files of the old domain's servers, and also deleting the PTR records for those machines from the old domain's hosts.rev files. Any optional HINFO and WKS records for the moved machines should also be deleted.

4. If you are splitting an existing domain, add the new subdomain name to CNAME records in the parent domain's master server hosts and file.

   For example, suppose you are using the machine aldebaran as a fax server and it had the following CNAME record in the hosts file of the parent domain's servers:

   faxserver IN CNAME aldebaran

   In addition to creating a new faxserver CNAME record for aldebaran in the hosts file of the new subdomain's master server, you would also have to change this CNAME record in the parent domain's hosts file to include aldebaran's subdomain as shown below:

   faxserver IN CNAME aldebaran.manf.doc.com

5. Add NS records for the new subdomain's servers to the parent domain's hosts file.

   For example, suppose that your parent domain is doc.com and you are creating a new manf.doc.com subdomain with the machine rigel as manf's primary master server and aldebaran as the secondary master server. You would add the following records to the hosts file of doc.com's primary master server:

   manf.doc.com 99999 IN NS rigel.manf.doc.com 99999 IN NS aldebaran.manf.doc.com

6. Add A records for the new subdomain's servers to the parent domain's hosts file.

   Continuing with the above example, you would add the following records to the hosts file of doc.com's primary master server:

   rigel.manf.doc.com 99999 IN A 1.22.333.121 aldebaran.manf.doc.com 99999 IN A 1.22.333.136

7. Start up named on the subdomain's servers.

   # /usr/sbin/in.named

   Instead of running in.named from the command line, you can reboot. See Solaris Naming Setup and Configuration Guide for details.