PTR and DNSSEC

[Hongbo Shi]

From: Joseph S D Yao <jsdy at cospo.osis.gov>
Subject: Re: PTR and DNSSEC
Date: Fri, 15 Dec 2000 07:54:42 -0500

> 
> On Fri, Dec 15, 2000 at 09:41:02AM +0900, Hongbo Shi wrote:
> > Hi, I have a question. Is a list of PTR records really necessary?
> > If we have 
> > 
> > www1   A    192.168.1.1
> > www2   A    192.168.1.1
> > www3   A    192.168.1.1
> > ...
> > 
> > Do you think we must have a list of PTR records? 
> > 
> > 1.1.168.192.in-addr.arpa.  PTR   www1.foo.com.
> > 1.1.168.192.in-addr.arpa.  PTR   www2.foo.com.            
> > 1.1.168.192.in-addr.arpa.  PTR   www3.foo.com.
> > ...
> > 
> > Do you think one is enough? Is the PTR record is just used for somebody want 
> > to check if "www1.foo.com." is mapped to 192.168.1.1 exactly? Is that all? 
> > Is there some other requirement? Such like DNSSEC won't move well without all
> > of the PTR records? 
> 
> You are exactly right - only one PTR record is needed for normal
> operations.  I don't think that DNSsec adds any requirement, but I
> don't yet have all of the DNSsec requirements down pat.

  Thanks a lot. 

  And could you please give me a bit detail on "normal operations"?
  As my understanding, "normal operations" is such like "traceroute", 
  "ping" ... . In other words, when somebody "ping/traceroute" some 
  IP address, in the responses if the IP address has a corresponding 
  PTR record then just return the domain name, right?
  ......why not just using IP address in those normal operations? 
  Because domain name has more meanings than IP address? Is that all? :P

  Best Regards.

Hongbo