a radical proposal (Re: protocols that don't meet the need...)

Michael.Dillon at btradianz.com Michael.Dillon at btradianz.com
Thu Feb 16 10:34:33 UTC 2006

>   - join a local IXP, which may be a physical switch or
>     virtualized by a set of bilateral agreements.

Why should they join an IXP if they already have
private peering arrangements?

>   - outside the region, they advertise the prefix of the
>     regional authority

Mixing government with operations? If you favor doing
that then why not just give IPv6 addresses to the various
national governments and let the UN sort it out?

Personally I disagree with any scheme which calls for 
national or municipal governments to assign IPv6 addresses
to end users. Dressing it up as a "regional authority"
does not make it any nicer.

Forcing people to join an unecessary IX is not the way
to solve the problem of regional aggregation of routes.
This is a purely technical problem which can be solved
by the RIR practices in allocating IPv6 addresses. If they
would allocate addresses in a geo-topological manner then
end users and ISPs would be free to aggregate routes 
outside of their region without any involvement of governments
or any requirement to join consortia or IXes. It does 
require the users of such geo-topological addresses to
ensure that in THEIR region, there is sufficient 
interconnectivity (physical and policy) between ISPs for
the addressing to work. But that does not need to be determined
or managed centrally.

Geo-topological addressing refers to RIRs reserving large
blocks of designated addresses for areas served my large
cities (over 100,000) population. When end users are located
in fringe areas roughly equidistant between two or more such
centers, the RIR simply asks the end user (or ISP) which is
the center to which they want to connect (communicate).
This addressing scheme operates in parallel with the existing
provider-oriented IPv6 addressing scheme but uses a different
block of IPv6 addresses out of the 7/8ths that are currently
reserved. No hardware or software changes are required for this
to work, merely some geographical/economical research to determine
the relative sizes of the address pool to be reserved for each
of the 

> Note that the customer is not expected to run BGP or get an AS 
> number, but either the regional authority gets an AS number or each 
> serving ISP is deemed authorized to originate the prefix in its BGP 
> announcements. But if a SOHO has two ISPs, both advertise its prefix 
> within the region, and when a packet is sent to the prefix from 
> wherever, any ISP that is delivering service to the SOHO can 
> legitimately deliver it, and if one gets the packet but is not the 
> servicing ISP, it knows how to hand the packet to the appropriate ISP 
> at the IXP.
> This turns the business model of routing on its head. Typically today 
> if Alice is using ISP AliceNet and Bob is using ISP BobNet, Alice 
> hands her packet to AliceNet, AliceNet gets it to BobNet in the 
> cheapest way it can, and BobNet carries it halfway around the world 
> to Bob. Bob's ISP carries the burden of most of the work. But in this 
> model, if AliceNet happens to also provide service in Bob's region, 
> AliceNet might carry the packet to the region and only give it to 
> BobNet for the last 500 feet.
> Whenever I have talked about the model with an ISP, I have gotten 
> blasted. Basically, I have been told that
> (1) any idea on operations proposed in the IETF is a bad idea because 
> the IETF doesn't listen to operators
> (2) the ISPs aren't going to be willing to make settlement payments 
> among themselves in accordance with the plan
> (3) routing isn't good enough to support it
> (4) and in any event, this makes it too easy to change ISPs
> In short, "hell no".
> So, since nobody in the IETF (according to you) is supporting this 
> model, what I understand from your remark and this thread is that the 
> IETF is not responsive to ideas proposed by operators and doesn't 
> come up with things operators can use, taking as an example that it 
> hasn't told you how to implement metropolitan addressing.
> Did I get that right?
> I'm not sure how to proceed, given the level of invective I get in 
> any discussion with anyone on the topic.
> Note 1: PI addressing for edge networks that can qualify under a 
> sensible set of rules (current ones are inadequate) for an AS number 
> is the preferred way to handle an enterprise of a size r complexity 
> comparable to a small (or large) ISP.
> Note 2: Provider-provisioned addresses continue to make sense for 
> folks that don't plan to multihome.

More information about the NANOG mailing list