Re: rfc1918 ignorant (fwd)

["Petri Helenius" <pete () he iki fi>]

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" <dave () ordinaryworld com>
To: <nanog () merit edu>
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: DOUGS () oceanic com
> To: oberman () es net
> Cc: dave () ordinaryworld com
> 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:oberman () es net> 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:oberman () es net> wrote on Wednesday, July 23,
> 2003 7:07 AM:]
> > > Date: Wed, 23 Jul 2003 08:59:18 -0400 (EDT)
> > > From: Dave Temkin <dave () ordinaryworld com>
> > > Sender: owner-nanog () merit edu
> > >
> > >
> > > 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.)