private/internal db file question...

Giorgos Keramidas keramida at
Thu Jun 23 00:56:38 GMT 2005

On 2005-06-22 17:13, Gary Kline <kline at> wrote:
> Folks,
> After years or trying, I may have my private/internal DNS db files
> working.  From a colo machine I can reach my internal servers.  One
> small question for the DNS wizards out there:: are the last
> "" lines considered good-form?  Can I blow them away or
> uncomment them?

Strip them off.

You didn't specify which zone this file was a database for, but looking at the
commented lines it seems like it's the reverse resolution database for (your internal network).  DNS records in zone files like this one
refer to addresses "relative" to the zone itself, which is probably defined as
the following in your named.conf configuration file:

    zone "0.0.10.IN-ADDR.ARPA" {
            type master;
            file "master/10.0.0.rev";

This definition of the zone in named.conf declares that addresses of the form
10.0.0.X will be looked up as PTR records of X in the file "master/10.0.0.rev"
under you named server root directory, i.e.

	ADDRESS		DB-FILE				RECORD	master/10.0.0.rev		1	master/10.0.0.rev		2
	...	master/10.0.0.rev		254

Usually, the most tricky part is grasping that "" is
what BIND looks up to find the name (or names) associated with the address (note the reversed byte order of the address parts).

> ;name    ttl    class    type    data
> 1        IN    PTR    localhost
> 1       IN    PTR    sage
> 220     IN    PTR    ethic
> 247     IN    PTR    tao
> 249     IN    PTR    zen

These look mostly ok, but you may want to fix the following:

  - "localhost" is usually assigned to, not
  - the "IN" column is *NOT* the TTL (time to live) of a record

> ;
> ;;  below may not be necessary
> ;

True; they're not.

> ;;;        IN      PTR
> ;;;        IN      PTR
> ;;;        IN      PTR
> ;;;        IN      PTR     ethic
> ;;;        IN      PTR     tao
> ;;;        IN      PTR     zen

Note that O'Reilly has an excellent book ("DNS & BIND") which you may
find immensely useful in setting up practically any sort of DNS server.

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