nanog mailing list archives

Re: BCP38 exceptions for RFC1918 space


From: Joe Greco <jgreco () ns sol net>
Date: Mon, 16 Aug 2010 06:50:00 -0500 (CDT)

What does "originating" mean?  Creating the packets?  Or forwarding
them?

Either way, there's no excuse.

First off, remember that BCP38 and 1918 don't apply on your set of
interconnected private networks, no matter how big a net it is.  You want to
filter between two of your private nets, go ahead.  You don't want to, that's
OK to.  The fun starts when those packets leave your network(s) and hit the
public Internet.

Now that we have that squared away...

Either that intermediate router originated the ICMP 'frag needed' packet, in
which case somebody needs to be smacked for originating a 1918-addressed packet
on the public internet, or it's forwarding the packet.  And if it's forwarding
the packet, then somebody *else* needs to be smacked for injecting that packet
into the public internet.

What *possible* use case would require a 1918-sourced packet to be traversing
the public internet? We're all waiting with bated breath to hear this one. ;)

It's great for showing in traceroutes who the heel is.

Do I win a prize?

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.


Current thread: