[30063] in North American Network Operators' Group
Re: RFC 1918
daemon@ATHENA.MIT.EDU (Patrick W. Gilmore)
Fri Jul 14 14:36:10 2000
Message-Id: <4.2.2.20000714142656.033f8340@ianai.net>
Date: Fri, 14 Jul 2000 14:33:18 -0400
To: nanog@merit.edu
From: "Patrick W. Gilmore" <patrick@ianai.net>
In-Reply-To: <Pine.LNX.4.21.0007141321410.3439-100000@Overkill.EnterZone
.Net>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format=flowed
Errors-To: owner-nanog-outgoing@merit.edu
[SNIP]
We had a similar discussion a long while ago (2 years?) on whether having
RFC1918 addressed router interface could break Path MTU discovery.
The general upshot is that the RFC specifically says that no packets with a
reserved address in the header (source or destination) should leave the
network in question. Also, the RFC says it is not at all unreasonable (but
not required) for a network to filter packets with RFC1918 addresses in the
source. (To prevent attacks and things like that.)
So it is nearly impossible to stay 100% compliant and address router
interfaces with RFC1918 addresses. (Unless you NAT or something.)
All IIRC - I did not dig up the thread to double-check.
TTFN,
patrick
P.S. Please do not yell at me about this, I am just summarizing a past
thread I thought might be relevant. I got yelled at enough during the last
thread where I argued that it was not such a bad thing 'cause it conserved
space and stuff. Really, I only need 14 people to point out the sections
of the RFC I missed before I get the point. :p
