Re: SMTP in distributed DOS

[Valdis.Kletnieks () vt edu]

On Sun, 20 Feb 2000 11:59:42 PST, I Am Not An Isp <patrick () ianai net>  said:
> This is the problem - a mail server stupid enough to send a bounce to an 
> unverified host name, instead of the connecting IP address.

Stupid or not, that's required by the RFCs.  Take a look at this mail,
the original From: points at 'vt.edu', which is MX'ed to mail.vt.edu.
However, that's NOT the address that the NANOG mailing list is receiving
this mail from.

For that matter, did the mail from 'ianai.net' arrive at the NANOG mailing
list *from* ianai.net? I see this in the headers:

Received: from pgilmore (PIX46.pgexch.com [208.217.23.46])  by pyrite.eod.onyx.net (8.9.3/8.9.3)

Hmm.. Must be spam we should have rejected, since there's a case to be made
that you shouldn't accept mail you can't send a bounce message back to, and
your mail obviously came from an unverified IP address...

Be careful what you ask for, you may get it...

-- 
                                Valdis Kletnieks
                                Operating Systems Analyst
                                Virginia Tech