rfc1918 ignorant

Wed Jul 23 17:40:03 UTC 2003

Except you're making assumptions as to how that router is used.

If it's being used for purely transit then your third paragraph doesn't
apply at all.  The traffic is not originating or terminating there, it is
merely passing through.

-- 
David Temkin

On Wed, 23 Jul 2003, David Schwartz wrote:

>
>
> > -----Original Message-----
> > From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu]On Behalf Of
> > variable at ednet.co.uk
> > Sent: Wednesday, July 23, 2003 6:10 AM
> > To: Dave Temkin
> > Cc: nanog at merit.edu
> > Subject: re: rfc1918 ignorant
> >
> >
> >
> > On Wed, 23 Jul 2003, Dave Temkin wrote:
> >
> > > 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?
> >
> > If Frank's seeing the IP in his traceroute then the network concerned
> > isn't properly filtering traffic leaving their borders as per BCP38:
> >
> > http://www.faqs.org/rfcs/bcp/bcp38.html
>
> 	They're not complying with RFC1918 either:
>
>    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).
>
>    All other hosts will be public and will use globally unique address
>    space assigned by an Internet Registry. Public hosts can communicate
>    with other hosts inside the enterprise both public and private and
>    can have IP connectivity to public hosts outside the enterprise.
>    Public hosts do not have connectivity to private hosts of other
>    enterprises.
>
> 	and
>
>    Because private addresses have no global meaning, routing information
>    about private networks shall not be propagated on inter-enterprise
>    links, and packets with private source or destination addresses
>    should not be forwarded across such links. Routers in networks not
>    using private address space, especially those of Internet service
>    providers, are expected to be configured to reject (filter out)
>    routing information about private networks. If such a router receives
>    such information the rejection shall not be treated as a routing
>    protocol error.
>
>    Indirect references to such addresses should be contained within the
>    enterprise. Prominent examples of such references are DNS Resource
>    Records and other information referring to internal private
>    addresses. In particular, Internet service providers should take
>    measures to prevent such leakage.
>
> 	It's pretty clear that devices with network layer connectivity outside the
> etnerprise are not private and thus can't be numbered inside private IP
> space.
>
> 	DS
>
>