Caching nameserver

From: Randy Sparks (none_at_none.com)
Date: 06/29/04 

Date: Tue, 29 Jun 2004 20:05:35 +0000 (UTC)

I've setup a caching namerserver using Fedora Core Linux. I took the easy
route and installed the Bind RPM, along with the caching-nameserver RPM.

It works fine and "dig" proves that it's looking up addresses.

The problem is the speed at which its cached DNS records expire. If I dig,
say, google.com, it takes around 500ms to get the record. I presume this is
because it's querying the TLDs. After this, a "dig" of google.com takes
around 3ms, which I again presume is because it's cached.

So far so good. The trouble is that 10 or so minutes later, digging
google.com means a fresh TLD lookup, and another half second wait. Then
after this it's back to 3ms.

I believe that the TLDs themselves set the expiration time for each record,
but surely 10 minutes is too brief a time? Is there any way to override
this setting? Ideally I'd like records to be cached for 24 hours.

Many thanks in anticipation of any help. If anybody can recommend a good
(and preferably plain English) guide to Bind, I'd be really grateful.