DNS forwarding: does it actually work?

[Barry Margolin]

In article <c3d1mk$6th$1 at sf1.isc.org>,
 Robert Abbate <tikvah7 at yahoo.com> wrote:

> from what I can tell, I have to update the named.conf
> file on the slave for every new host anyway...correct?

No.  Only for new zones, not new hosts.  Although maybe as a web hosting 
company, every new host is a new zone for you.

> 
> I am looking for a solution that could basically
> replicate the master name server (ns1) over to ns2
> which is a different machine. Any additions/changes
> done to ns1 replicate to ns2 automatically is ideal
> for me (and preferrably without having to manually
> update/change the named.conf file on the ns2 if
> possible). 
> 
> We have a webhosting company, and zones are created
> and update often. Currently, I have them as both
> masters and the configuration is manually copied to
> the ns2 once daily...I would like something LIVE
> updating (if Bind has that ability).

If you need added/deleted zones to be replicated, you'll have to write 
your own script to copy over the named.conf file, changing master zones 
to slaves.  Or you could do what my company did: generate the named.conf 
and zone files for all the servers from a database.

The DNS protocol doesn't provide any way to get the list of zones on a 
server.  So without some implementation-specific mechanism, there's no 
way for BIND to automatically replicate the entire configuration of a 
server.  You have to manually configure the list of zones that a slave 
should pull from the master.

> When i did set up ns2 as a slave, the actual data said
> it was copied over, but it wasn't. The zones were
> empty on the slave. 

Check the logs, there must have been errors occurring.  Many poeple 
operate slave servers with no problems.

> 
> Besides, as a slave, doesn't it basically only forward
> requests to ns1 (master)? I want it only to forward
> requests to ns1 when ns1 is UP. If ns1 goes down, I
> need ns2 to give answers.

No, a slave copies the zone files from the master whenever they change, 
and then responds to queries in those zones directly.  It never forwards 
queries in those zones.

Do you have a copy of "DNS & BIND"?

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***