On Thu, 2006-01-05 at 22:41, Tim Edwards wrote:
> Les Mikesell wrote:
>
> >
> >
> > No, it describes what happens when a large number of clients are
> > behind the same local DNS server - and not very realistically
> > at that.
>
> It describes what happens with a typical ISP where all the users are
> looking up addresses using the ISP's caching nameservers, this is not a
> local network. If it was a local network I was dealing with I could just
> have all the clients resolve off the one DNS server and there'd be no
> propagation delay. The problem with the Internet is the propagation
> delay out to all those seperate ISP's caching nameservers.
If all of your users connect through the same ISP, perhaps you
should consider moving the server(s) to a data center provided
by that ISP to reduce the chances they would be unreachable.
However, even when everyone uses the same DNS cache a new lookup
should happen every time the TTL expires so unless everyone
connects at the same time you should still get random distribution.
If the ISP's DNS server doesn't observe the DNS TTL (you can
watch it count down with 'dig'), find a different ISP or
hand-configure the clients to use servers that work.
--
Les Mikesell
lesmikesell at gmail.com