[164924] in North American Network Operators' Group
Re: Spoofing ASNs (Re: SNMP DDoS: the vulnerability you might not
daemon@ATHENA.MIT.EDU (Florian Weimer)
Sun Aug 11 08:45:09 2013
From: Florian Weimer <fw@deneb.enyo.de>
To: Jared Mauch <jared@puck.nether.net>
Date: Sun, 11 Aug 2013 14:45:30 +0200
In-Reply-To: <F25A9459-761A-4F04-AF00-EC25EAE2A42D@puck.nether.net> (Jared
Mauch's message of "Thu, 8 Aug 2013 13:45:03 -0400")
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
* Jared Mauch:
> Number of unique IPs that spoofed a packet to me. (eg: I sent a
> packet to 1.2.3.4 and 5.6.7.8 responded).
That's not necessarily proof of spoofing, isn't it? The system in
question might legitimately own IP addresses from very different
networks. If the system is a router and the service you're pinging is
not correctly implemented and it picks up the IP address of the
outgoing interface instead of the source address of the request,
that's totally expected.
I'm not saying that BCP 38 is widely implement (it's not, unless
operators have configured exceptions for ICMP traffic from private
address, which I very much doubt). I just think you aren't actually
measuring spoofing capabilities.
