Re: negative_dns_ttl in STABLE5

On Mon, Oct 18, 1999 at 11:53:06AM +0200, Charles Bruneteau wrote:
> Henrik Nordstrom wrote:
> > Charles Bruneteau wrote:
> > > Each time i reload for www.yahoo.com from my browser, my proxy asks a dnsserver
> > > process for a resolution.
> > >
> > > Is this a bug or common behaviour ?
> >
> > It is a feature.
> >
> > "Pragma: no-cache" invalidates both object and DNS caches.
>
> Are you certain of this Henrik ?
>
> I modified a web server IP address and reported it in our DNS; then,
> even with "Pragma: no-cache" , i was not able anymore to access the
> server. I verified manually that dnsserver was reporting the new IP
> address. I guess ipcache was still used.

  I've also observed this behavior with 2.2S4. I had been attributing
it to the dnsserver processes, but I didn't think to try querying them
directly.

  I think the DNS resolution with www.yahoo.com may be because they use
a very short DNS TTL; I just queried our name server and saw 87 seconds
remaining on their TTL. Probably left over from the old "rotating DNS"
hack for load distribution?
  -- Clifton

-- 
 Clifton Royston  --  LavaNet Systems Architect --  cliftonr@lava.net
        "An absolute monarch would be absolutely wise and good.  
           But no man is strong enough to have no interest.  
             Therefore the best king would be Pure Chance.  
              It is Pure Chance that rules the Universe; 
          therefore, and only therefore, life is good." - AC