how DNS client perform reverse lookup

[Barry Margolin]

In article <ct3ioj$1qll$1 at sf1.isc.org>, Keith Ng <ngkeith at triumf.ca> 
wrote:

> Hi,
> 
> Would someone tell me how DNS client perform reverse lookup? Is there 
> any root servers like forwards lookup for the in-addr.apra domain?

They start from the normal root servers.  These servers have delegation 
records for in-addr.arpa, just like they do for com, net, etc.  The 
client servers follow this reverse delegation in exactly the same way 
that they follow forward delegations.  As far as the nameservers are 
concerned, there's no difference between forward and reverse DNS; 
everything is just arbitrary labels to the servers and resolvers.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***