nanog mailing list archives
Re: General question on rfc1918
From: Robert Bonomi <bonomi () mail r-bonomi com>
Date: Tue, 13 Nov 2007 09:35:34 -0600 (CST)
From owner-nanog () merit edu Tue Nov 13 09:12:04 2007 Cc: "nanog () merit edu" <nanog () merit edu> From: Joe Abley <jabley () ca afilias info> To: Drew Weaver <drew.weaver () thenap com> Subject: Re: General question on rfc1918 Date: Tue, 13 Nov 2007 10:10:26 -0500 On 13-Nov-2007, at 10:08, Drew Weaver wrote:Hi there, I just had a real quick question. I hope this is found to be on topic. Is it to be expected to see rfc1918 src'd packets coming from transit carriers?You should not send packets with RFC1918 source or destination addresses to the Internet. Everybody should follow this advice. If everybody did follow that advice, you wouldn't see the packets you are seeing.
Really? What do you do if a 'network internal' device -- a legitimate use of RFC1918 addresses -- discovers 'host/network unreachable' for an external-origin packet transitinng that device? <evil grin> Your comment _is_ "generally correct", but there are some significant 'corner cases' that do complicate life. Packets that could conceivably generate a reply/response and have an RFC 1918 address (source -or- dest) should be ingress *and* egress filtered -- unless there is specific agreement with the adjacent network with regard to coordinated use of specific portions of that space. Packets which are strictly error/status reporting -- e.g. IMP 'unreachable', 'ttl exceeded', 'redirect', etc. -- should *NOT* be filtered at network boundaries _solely_ because of an RFC1918 source address.
Current thread:
- Re: General question on rfc1918, (continued)
- Re: General question on rfc1918 Joe Abley (Nov 13)
- RE: General question on rfc1918 Darden, Patrick S. (Nov 13)
- Re: General question on rfc1918 Justin M. Streiner (Nov 13)
- RE: General question on rfc1918 Drew Weaver (Nov 13)
- Re: General question on rfc1918 Joe Greco (Nov 13)
- Re: General question on rfc1918 Sean Donelan (Nov 13)
- Another question on rfc1918 Michael Painter (Nov 23)
- Re: Another question on rfc1918 Robert E. Seastrom (Nov 23)
- Re: Another question on rfc1918 Randy Bush (Nov 23)
- Re: Another question on rfc1918 Bruce M Simpson (Nov 24)
- Re: General question on rfc1918 Robert Bonomi (Nov 13)
- Re: General question on rfc1918 Joe Abley (Nov 13)
- Re: General question on rfc1918 Phil Regnauld (Nov 13)
- Re: General question on rfc1918 Joe Abley (Nov 13)
- Re: General question on rfc1918 Paul Ferguson (Nov 13)