Slave nameserver question

[Barry Margolin]

In article <gc22q7$omh$1 at sf1.isc.org>,
 Matus UHLAR - fantomas <uhlar at fantomas.sk> wrote:

> > > Cherney John-CJC030 wrote:
> > > > Besides being a bad idea from a general design perspective, is it
> > > > possible to set up a nameserver as a slave for a domain, but have the
> > > > masters field point to itself? ("I am a slave for this information, and
> > > > the master is myself.") In thinking about it, it seems like it should be
> > > > OK. The slave will always be able to contact the master, so the data
> > > > should never go stale. The serial number is always up to date, so there
> > > > won't be any bandwidth used in zone transfers. Is there something
> > > > somewhere that would make this not work? (Something in the code for
> > > > executing refreshes or parsing the named.conf file?) 
> 
> On 01.10.08 22:03, Barry Margolin wrote:
> > Maybe what he's really planning on doing is listing two masters: the 
> > real master and itself.  Pointing to the real master causes updates to 
> > propagate, pointing to itself prevents expiration.
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Does it? I'd expect that expiration status only depends on setting in
> named's config, not content of the SOA record.

There's no expiration setting in the named.conf.  Expiration depends on 
the EXPIRE field of the SOA record, and occurs if the slave is unable to 
query the master for the SOA record for that length of time.  If the 
master is itself, these SOA queries should always succeed, so the zone 
won't expire.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE don't copy me on replies, I'll read them in the group ***