Installing and Administering Internet Services

96 Chapter 3

Conﬁguring and Administering the BIND Name Service

Delegating a Subdomain

Within your own domain, you may delegate any number and level of

subdomains to distribute control and management responsibility. These

subdomains need not be registered with the parent network. The

organization that owns a zone or subdomain is responsible for

maintaining the data and ensuring that up-to-date data is available from

multiple, redundant servers.

Follow these steps to add a subdomain:

1. Set up the name servers for the subdomain.

2. Edit the existing zone ﬁle, db.domain on the name server for the

parent domain, as follows:

• Add an NS resource record for each server of the new domain.

• Add A records to specify the internet addresses of the name

servers listed in the NS records.

Following are some lines from the example ﬁle db.nmt. Hosts

venus.nmt.edu and moon.nmt.edu are name servers for the

nmt.edu domain. Each of these hosts has two connections to the

network, so each requires two A records: one for each of its internet

addresses.

nmt.edu. 86400 IN NS venus.nmt.edu.

86400 IN NS moon.nmt.edu.

venus.nmt.edu. 86400 IN A 123.4.5.678

86400 IN A 45.6.7.890

moon.nmt.edu 86400 IN A 67.8.9.10

3. After modifying the domain data ﬁles, issue the following command to

restart the name server for the parent domain and force it to reload

its databases:

/usr/sbin/sig_named restart