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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: rfc1918 ignorant (fwd)
So this, as many other discussions in the past, ends with the conclusion that ARIN did their share of breaking RFC´s and the Internet ? Pete ----- Original Message ----- From: "Dave Temkin" <[email protected]> To: <[email protected]> Sent: Wednesday, July 23, 2003 9:11 PM Subject: RE: rfc1918 ignorant (fwd) > > ---------- Forwarded message ---------- > Date: Wed, 23 Jul 2003 07:53:26 -1000 > From: [email protected] > To: [email protected] > Cc: [email protected] > Subject: RE: rfc1918 ignorant > > There's a common misconception reflected here that I wanted to correct. I > don't have nanog-post, so I apologize if its not appropriate to reply > directly. You may repost my comments if you'd like. > > [Kevin Oberman <mailto:[email protected]> wrote on Wednesday, July 23, > 2003 7:07 AM:] > > Comcast and many others seem to > > blithely ignore this for convenience sake. (It's not like they need a > > huge amount of space to give private addresses to these links.) > > ARIN required cable operators to use RFC 1918 space for the management > agents of the bridge cable modems that have been rolled out to the millions > of residential cable modem customers. Doing so obviously requires a 1918 > address on the cable router, but Cisco's implementation requires that > address to be the primary interface address. There is also a publicly > routable secondary which in fact is the gateway address to the customer, but > isn't the address returned in a traceroute. Cisco has by far the lead in > market share of the first gen Docsis cable modem router market so any trace > to a cable modem customer is going to show this. > > In fact, Comcast and others _do_ need a huge amount of private IP space > because of this. We didn't "blithely ignore" the RFC, but didn't have a > choice in implementation. Perhaps Cisco will improve their implementation > for the next round of CMTS development... > > Filtering of RFC 1918 space by cable ISPs is of course another topic. > > -Doug- > > [Kevin Oberman <mailto:[email protected]> wrote on Wednesday, July 23, > 2003 7:07 AM:] > >> Date: Wed, 23 Jul 2003 08:59:18 -0400 (EDT) > >> From: Dave Temkin <[email protected]> > >> Sender: [email protected] > >> > >> > >> Is this really an issue? So long as they're not advertising the > >> space I see no issue with routing traffic through a 10. network as > >> transit. If you have no reason to reach their router directly (and > >> after Cisco's last exploit, I'd think no one would want anyone to > >> reach their router directly :-) ), what's the harm done? > >> > >> RFC1918 merely states that it shouldn't be routed on the global > >> internet, not that it can't be used for transit space. > > > > That's not what is in my copy of 1918. > > > > "In order to use private address space, an enterprise needs to > > determine which hosts do not need to have network layer connectivity > > outside the enterprise in the foreseeable future and thus could be > > classified as private. Such hosts will use the private address space > > defined above. Private hosts can communicate with all other hosts > > inside the enterprise, both public and private. However, they cannot > > have IP connectivity to any host outside of the enterprise. While not > > having external (outside of the enterprise) IP connectivity private > > hosts can still have access to external services via mediating > > gateways (e.g., application layer gateways)." > > > > As I read this, packets with a source address in 19298 space should > > NEVER appear outside the enterprise. Comcast and many others seem to > > blithely ignore this for convenience sake. (It's not like they need a > > huge amount of space to give private addresses to these links.) >
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