Re: Nameserver calls - libesmtp problem?

[Brian Stafford <brian stafford uklinux net>]

On Thu, 21 June 14:58 Carlos Morgado wrote:

| backtrack ... libESMTP is doing ns lookups for 'localhost' ?
| unless albrecht's system is messed up that is soo wrong.

A quick followup:

I've searched through the RFCs looking for normative information on
the implementation of gethostbyname().  No luck.  Basically the
closest thing to a normative requirement is that systems connected
to the internet are required to use the DNS for mapping names to
IP addresses.  So it looks like the exact behaviour is dependent
on your system's implementation of gethostbyname().

However, from RFC 1537:

   Note that all domains that contain hosts should have a "localhost" A
   record in them.

and in RFC 1912:

   The "localhost" address is a "special" address which always refers to
   the local host.  It should contain the following line:

           localhost.      IN      A       127.0.0.1

This implies that all conformant implementations are expected to use
DNS to resolve "localhost" to 127.0.0.1 or at least that localhost
is defined in DNS to catch cases where the resolver library hard
codes the resolution.

As it is, I see no reason to hard code libESMTP behaviour for
localhost nor would I reccomment other software authors to do so
in their own programs.

Brian