Bind: question about forwarding

[Simon Waters]

Barry Margolin wrote:
> 
> In article <9n8jpo$778 at pub3.rc.vix.com>,
> FD <fabrice.ducourtioux at diplomatie.fr_nospam> wrote:
> >I use two DNS servers. The first one (A) is used to resolve any query
> >(except .state.wash.com, an unknwon domain on Internet). The second one (B)
> >is used to resolv only .state.wash.com. I can only use server A from my LAN.
> >Is it possible to re-write any query of kodi.wash.com to the name server A
> >for kodi.state.wash.com and to forward this query on the server B (which is
> >able to resolve such domain). In case of B is unable to respond such
> >request, I would ask the Internet from server A to resolv only
> >kodi.wash.com.
> 
> BIND can do the forwarding (using a "type forward" zone), but there's no
> built-in feature to do the rewrite.  BIND is open source, so you can make
> it do whatever you want if you're willing to do some programming.

Cough - DNAME - Cough, but I don't think this does exactly what
they want, as it won't pass the query on as originally written,
unless the DNAME is on server B perhaps....

So query to A is www.kodi.wash.com, which is forwarded to B (But
not forward-only in case B is dead)

B has a DNAME which rewrites it as "www.kodi.state.wash.com" 

B can answer that as it is "state.wash.com" - but must avoid
poisoning A so be careful on options and such like.

Did I miss something?

This comes under interesting mental exercise, but you wouldn't
want to do it for real, and you really wouldn't want to be the
admin who inherited such a knotted configuration.

Fabrice, 

why the need to convolute domain names? 

Why would you give a different answer if B is down? This might
make sense if all the records had short TTL, and B was some sort
of optional device, or probe.

Why doesn't there exist a C, secondary to B, and also listed as
a forwarder on A?