Problems with bind9 caching too long

[Ronan Flood]

Fred Viles <fv+abuse at nospam.usen.epitools.com> wrote:

> Phil Dibowitz <phil at usc.edu> wrote:
>
> > No - that's my point... the TTL of the NS records isn't being
> > obeyed!
> 
> But that's wrong.  It's not that the TTL isn't being obeyed, it's 
> that the TTL of the NS records isn't being exceeded.  Every time a 
> caching server makes a query for any name in the domain to the 
> authoritative server, it gets a fresh copy of the authoritative NS 
> records and starts a fresh TTL countdown.

Apparently so, but Phil thinks it shouldn't.  I agree with him (FWIW),
the fresh copies of the NS records should not override the TTL on the
existing NS records in the cache; they should be allowed to count down
and expire, forcing new lookup via the delegation from the parent zone.

-- 
                      Ronan Flood <R.Flood at noc.ulcc.ac.uk>
                        working for but not speaking for
             Network Services, University of London Computer Centre
     (which means: don't bother ULCC if I've said something you don't like)