The End-To-End Internet (was Re: Blocking MX query)

Jay Ashworth jra at
Tue Sep 4 18:22:54 UTC 2012

----- Original Message -----
> From: "Owen DeLong" <owen at>

> I am confused... I don't understand your comment.

It is regularly alleged, on this mailing list, that NAT is bad *because it 
violates the end-to-end principle of the Internet*, where each host is a
full-fledged host, able to connect to any other host to perform transactions.

We see it now alleged that the opposite is true: that a laptop, say, like
mine, which runs Linux and postfix, and does not require a smarthost to
deliver mail to a remote server *is a bad actor* *precisely because it does
that* (in attempting to send mail directly to a domain's MX server) *from 
behind a NAT router*, and possibly different ones at different times.

I find these conflicting reports very conflicting.  Either the end-to-end
principle *is* the Prime Directive... or it is *not*.

-- jra
Jay R. Ashworth                  Baylink                       jra at
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates         2000 Land Rover DII
St Petersburg FL USA               #natog                      +1 727 647 1274

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