Selective DNS replies

Thu Apr 25 08:18:27 UTC 2002

Hey Chris ;)

On Thu, 25 Apr 2002, Christopher L. Morrow wrote:
> I believe this is in the context of:
> 'hax0r _bob (for instance) has a PTR for his ip which says
> "I.love.humble.net" when machines a->y query for the PTR, BUT when machine
> z queries it returns "www.cert.org"'

Hmmm, yes and no :-)

> I could be off base here, but I think this is the question Avleen is
> asking, eh?

I was asking about almost the opposite.

Actual scenario is this:
  Load balancing WWW and IRC servers.
I believe this use of load-balanced DNS would be a fairly typical use.
I want all users from IP space allocated to ARIN to go to my US web and
IRC servers. I want all other users to go to my EU based servers.
I want to maintain two primary servers in each continent as hubs across
which all traffic flows, and data is sync'd.

As someone clearly pointed out to me, people have taken IP space from
these regions and ported it to other places in the world. While this may
be true, I believe it's use is small enough that I don't have to worry
about it too much.

On the other hand what you point out would be a very important effect for
this. Potentially a good way to obfuscate your hostnames to either a small
select group, or to the whole world.