AOL rejecting mail from IP's w/o reverse DNS ?

Crist Clark crist.clark at
Fri Dec 5 00:59:59 UTC 2003

Adam McKenna wrote:
> On Thu, Dec 04, 2003 at 02:04:54PM -0800, Crist Clark wrote:
> >   $ dig soa
> >   $ dig soa
> This email contains approximately the same information as Randy's did.  Yes,
> the SOA's will be different.  That is what is intended.  The nameserver that
> is authoritative for is delegating
> to  Were you trying to make some other point or just showcasing
> your 'dig' skills?

Sorry, I was not clear. I was looking at the examples on the webpage that
was pointed to previously. The pain killers for my injured foot have made
me a bit fuzzy today. You could set things up to look a little less broken
than in his examples. I guess you can get around,

  $ dig @<isp-server> soa

  $ dig @<your-server> soa

Breaking your own server, by setting up a zone for each IP address. Not

You have domains with A records. Uck.

It's based on a strange premise. From that web page,

  The fundamental mistake made by the authors of RFC 2317 is that it 
  didn't occur to them that a delegation from a superdomain's content 
  DNS servers does not have to point to the apices of the "zones" in 
  the subdomain's content DNS servers. Or, put another way, it is not 
  necessary for the apex of a "zone" to be a domain that the rest of 
  the world considers to be within the content DNS server's bailiwick. 

Whereas I think the "mistake" they made seems to be that they follow

  - NAME SERVERS are server programs which hold information about
    the domain tree's structure and set information.
    ...                                              Name servers
    know the parts of the domain tree for which they have complete
    information; a name server is said to be an AUTHORITY for
    these parts of the name space.  Authoritative information is
    organized into units called ZONEs, and these zones can be
    automatically distributed to the name servers which provide
    redundant service for the data in a zone.

All of that aside, I don't see how it is any easier than RFC2317. In
fact you double the number of records when you add additional nameservers
to your zone (which isn't really a zone). To quote one of his examples,
I don't see how getting your ISP to do,

  $GENERATE 0-15 $ NS a.ns.$
  $GENERATE 0-15 a.ns.$ A

Is any harder than,

  $GENERATE 0-15 CNAME $.0/28
  0/28		NS

Crist J. Clark                               crist.clark at
Globalstar Communications                                (408) 933-4387

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