Chapter 18. Berkeley Internet Name Domain

BIND performs name resolution services using the named daemon. BIND lets users locate computer resources and services by name instead of numerical addresses.
In Red Hat Enterprise Linux, the bind package provides a DNS server. Run the following command to see if the bind package is installed:
~]$ rpm -q bind
package bind is not installed
If it is not installed, use the yum utility as the root user to install it:
~]# yum install bind

18.1. BIND and SELinux

The default permissions on the /var/named/slaves/, /var/named/dynamic/ and /var/named/data/ directories allow zone files to be updated using zone transfers and dynamic DNS updates. Files in /var/named/ are labeled with the named_zone_t type, which is used for master zone files.
For a slave server, configure the /etc/named.conf file to place slave zones in /var/named/slaves/. The following is an example of a domain entry in /etc/named.conf for a slave DNS server that stores the zone file for testdomain.com in /var/named/slaves/:
zone "testdomain.com" {
			type slave;
			masters { IP-address; };
			file "/var/named/slaves/db.testdomain.com";
		       };
If a zone file is labeled named_zone_t, the named_write_master_zones Boolean must be enabled to allow zone transfers and dynamic DNS to update the zone file. Also, the mode of the parent directory has to be changed to allow the named user or group read, write and execute access.
If zone files in /var/named/ are labeled with the named_cache_t type, a file system relabel or running restorecon -R /var/ will change their type to named_zone_t.