caching only name server on mail gateway

noir911 · 11-01-2009, 01:21 AM

I am trying to setup a caching only name server on mail gateway and wondering if I am doing it right. Here is what I have done on RHEL 5.4.

Installed RPMs:

caching-nameserver-9.3.6-4.P1
bind-libs-9.3.6-4.P1
bind-utils-9.3.6-4.P1
bind-chroot-9.3.6-4.P1
bind-9.3.6-4.P1

I have never touched the file /etc/named.caching-nameserver.conf as it says: "DO NOT EDIT THIS FILE - use system-config-bind or use an editor to create named.conf - edits to this file will be lost on caching-nameserver package upgrade."

Created the /var/named/chroot/etc/named.conf
file with the following:

Code:

options {
       listen-on port 53 { 127.0.0.1; };
       directory       "/var/named";
       dump-file       "/var/named/data/cache_dump.db";
       statistics-file "/var/named/data/named_stats.txt";
       memstatistics-file "/var/named/data/named_mem_stats.txt";

       // My primary, secondary DNS servers
       forwarders {203.90.12.33; 203.90.18.21;};
       forward first;

       // maximum time (in seconds) for which the server will cache
       // positive answers
       // set to four hours.

       max-cache-ttl 14400;

       allow-query     { localhost; };
       allow-query-cache { localhost; };
};

logging {
       channel default_debug {
               file "data/named.run";
               severity dynamic;
       };
};
view localhost_resolver {
       match-clients      { localhost; };
       match-destinations { localhost; };
       recursion yes;
       include "/etc/named.rfc1912.zones";
};

- created a symlink and changed ownership of named.conf: ln -sf /var/named/chroot/etc/named.conf /etc/named.conf && chown root:named /var/named/chroot/etc/named.conf

- here is my /etc/resolv.conf output:

search mydomain.com
nameserver 127.0.0.1

Everything is working fine: I can resolve DNS queries using 127.0.0.1 as my DNS server.

Have I done the setup correctly? Anything I am missing?

Thanks.

bathory · 11-01-2009, 01:52 AM

Hi,

This setup is not exactly a caching dns. It's more likely a forwarding/caching dns:
Your server will forward its queries to the servers defined in the "forwarders" line and will cache the response. Only if the forwarders are down it will use the "." hint zone, defined in /etc/named.rfc1912.zones, to query the root servers. In caching name servers only the hint zone is used.

Regards