Redhat DNS Caching

Caching only DNS server

Requests to remote DNS servers can take a long time. A caching server stores recent requests so that it can respond without forwarding the request to another DNS server.

Configuration

When looking a the default named.conf file, you will see that it is set up to create a caching only DNS server.

The options directive contains several directives including:

• Listen-on port / Listen-on-v6 port - this specifies the TCP/IP port. To extend this to the local network a network address of the network card needs to be added.

listen-on port 53 {127.0.0.1; 192.168.122.50}

• The directory directive specifies the location of the DNS data files. If the bind-chroot package is installed these files are hard linked to /var/named/chroot

• dump-file specifies the cache location and output location from rndc flush

• statistics-file specifies the cache location and output location from rndc stats

• memstatistics-file specifies the location of the memory usage statistics

• allow-query lists the ips allowed to get data from the server

• dnssec-* specifies the security options