[100814] in North American Network Operators' Group
Re: General question on rfc1918
daemon@ATHENA.MIT.EDU (Sean Donelan)
Tue Nov 13 11:23:44 2007
Date: Tue, 13 Nov 2007 11:12:41 -0500 (EST)
From: Sean Donelan <sean@donelan.com>
To: Drew Weaver <drew.weaver@thenap.com>
cc: "nanog@merit.edu" <nanog@merit.edu>
In-Reply-To: <B7152C470C9BF3448ED33F16A75D81C14D0FDF0265@exchanga.thenap.com>
Errors-To: owner-nanog@merit.edu
On Tue, 13 Nov 2007, Drew Weaver wrote:
> Is it to be expected to see rfc1918 src'd packets coming from transit carriers?
Yes. Any ISP which uses RFC1918 on "internal" links may generate
various ICMP error packets (e.g. traceroute/TTL expire, PMTU
discovery/Fragmentation required, etc) from router interfaces which have
RFC1918 addresses for transit traffic.
Some people filter them anyway, and get "*"'s in traceroutes and PMTU
weirdness.
#include "old debate about using RFC1918 addresses on transit links"
#include "other old debate about filtering stuff in backbones or edge"
