[156530] in North American Network Operators' Group
Re: The Department of Work and Pensions, UK has an entire /8
daemon@ATHENA.MIT.EDU (Cutler James R)
Wed Sep 19 10:09:09 2012
From: Cutler James R <james.cutler@consultant.com>
In-Reply-To: <20120919132416.GA28155@jeeves.rigozsaurus.com>
Date: Wed, 19 Sep 2012 10:07:52 -0400
To: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Sep 19, 2012, at 9:24 AM, John Osmon <josmon@rigozsaurus.com> wrote:
> On Wed, Sep 19, 2012 at 12:07:33AM -0500, Jimmy Hess wrote:
>> Assume you have a public IPv4 assignment, and someone else
>> starts routing your assignment... "legitimately" or not, RIR =
allocation
>> transferred to them, or not.
>>=20
>> There might be a record created in a database, and/or internet =
routing
>> tables regarding someone else using the same range for a connected =
network.
>>=20
>> But your unconnected network, is unaffected.
>=20
> Ahh... But the network may not be unconnected. Just because *you*
> don't have a path to it doesn't mean others are similarly =
disconnected.
> All of those "others" would be affected.
>=20
>> You are going to have a hard time getting a court to take your case,
>> if the loss/damages to your operation are $0, because your network =
is
>> unconnected, and its operation is not impaired by someone else's use,
>> and the address ranges' appearance in the global tables.
>=20
> Think about a company that has thousands of private interconnects with
> other companies. Unique address space would remove the chance of
> RFC1918 space clash, and any of the bad effects of NAT. (e.g The =
network
> *works* as it was originally designed.)
>=20
> Such a network would not have $0 in loss/damage when the partners =
can't
> reach it due to a rogue announcement.
>=20
> The Internet is not the same from all viewpoints.
>=20
This discussion is repeating ones heard hear in the mid 1990s. =20
Having a block of IP addresses not seen in YOUR IP routing tables is NOT =
evidence of unused addresses. For example, an inter-network SMTP relay =
correctly forwards messages via MX DNS entries only if unique IP address =
exist on both sides of the relay. This is just one example of =
application level gateways used to isolate networks at Layer 3 that has =
been in use for decades. =20
As noted above, there are many instances of private interconnects which =
rely on assigned integers to tag destinations in a globally unique =
fashion. In the case of IP addressing, IANA and the various registries =
provide this globally unique assignment service. Use of these unique =
integers for packet routing is left as an exercise for the Network =
Engineer. IANA and the registries are not in the business of directly =
policing the use of any assigned integers.
Those of us who have been involved in interconnecting private networks =
with overlapping IP address assignments are well aware of the pitfalls, =
hazards, and costs of using non-unique addressing.=20
An entity which uses its ignorance of how addresses are used internally =
by another entity as an excuse to ignore proper IP address assignment is =
deliberately contributing to network chaos and to the culture of =
ignoring rules "because we can".
The bottom line is that "Connected" does not mean "Routable via =
IPv4/IPv6". This is in addition to "Hidden" does not mean "Unused" as =
pointed out by others.
