AT&T SMTP Admin contact?

Valdis.Kletnieks at vt.edu Valdis.Kletnieks at vt.edu
Tue Nov 24 23:15:52 UTC 2009


On Tue, 24 Nov 2009 16:38:33 EST, Brad Laue said:

> True, but wouldn't a blacklist of SPF records for known spam issuing
> domains be a more maintainable list than an IP block whitelist?
> 
> (I'm no doubt missing something very obvious with this question)

140M+ .com where a malicious DNS server in East Podunk can be authoritative for
a domain actually in Bratslavia and domains are cheap and throw-away.

16M /24's, where you (mostly(*)) need to be able to actually route the packets,
so if you have a /24 in Bratslavia, you need something resembling a router
in Bratslavia as well, and somebody willing to light up the other end of
the cable, and you need a way to make BGP announcements (legal or otherwise ;)
to be able to exploit it.

Choose wisely which you'd rather use for defense.

(*) Mostly - though the BGP hack demonstrated at last year's DefCon
did qualify as an Epic Win for kewl presentations. ;)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 227 bytes
Desc: not available
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20091124/490cb96b/attachment.sig>


More information about the NANOG mailing list