Where to buy Internet IP addresses

Tue May 5 20:38:43 UTC 2009

> Joe Greco wrote:
> > Now, the question is, if you're sending all these prefix requests up to
> > the ISP's router, why is *that* device able to cope with it, and why is
> > the CPE device *not* able to cope with it?
> 
> The CPE cannot cope with it due to lack of a chaining standard and the 
> lack of customer understanding of configuring a router. An ISP, as 
> currently designed will manually assign prefix lengths and how they are 
> handed out at each layer of the network. A home user should not be 
> expected to understand this level of complexity. A CPE would have to be 
> told HOW to divide it's variably received prefix to assign it's own 
> networks and then issue prefixes to other routers behind it.

That doesn't seem like a problem from the set of unsolvable problems.
We have current protocols that do substantially more complicated things
in a standard and interoperable way.  Your average current everyday IPv4
CPE has a DHCP server on it, for example, which very roughly approximates
the complexity of the issue.

> What is missing, unless I've missed a protocol (which is always 
> possible), is an automated way for a CPE to assign it's networks, pass 
> other networks out to downstream routers in an on-need basis. I say 
> on-need, as there may be 3 routers directly behind the CPE and each of 
> those may get additional routers and so on and so forth. A presumption 
> could be made that route efficiency is not necessary at this level. ie, 
> would it be practical or expected that an automatically configured 
> network support > 100 routes or whatever a CPE can normally handle?

Actually, my own belief is that this /would/ be practical, and it might
even be made to work efficiently.

A "home router" maintains a list of space that it has been delegated, and
a list of actually-used space (assigned to directly connected interfaces,
along with any routed blocks).

Upon receipt of a delegation request, the router starts an algorithm to
see what it can do.

Because it has been allocating out of a /56, the "primary" /64 was 
delegated at offset 0.  Two requests from secondary routers came in, one
was offered a /64 at offset 128, one at offset 192.  That ought to make
reasonable sense.

The first "secondary" router learns that it has a bunch of downstream
routers, and in the worst case asks for a delegation one at a time for
each.  The primary router assigns the subnet at offset 129, updates its
route to the larger netmask, and away it goes.  There's actually no 
increase in the number of forwarding entries, and this can be done a
number of times.  Further, if the primary router decides that it is
allocating a lot of space to a secondary router, it can assign a larger
hunk of space, saving some setup time, or it can try to optimize for bit
boundaries.

Not all cases will be this optimal.  However, it seems reasonable to try.

> Of course, if this support is built at a CPE level, there's no reason 
> the protocol can't be extended and supported at the ISP level as well 
> for those who wish to utilize it. An ISP, would of course prefer prefix 
> aggregation and controls to set minimum and maximum aggregate space for 
> a customer.

Exactly.

> > You have an ISP network, with a large amount of space available, and a
> > lesser amount of space dedicated to the POP.
> 
> This setup in the ISP network is handled by hopefully clueful engineers 
> and probably not automatically assigned by some cool protocol that 
> routers speak (which would be cool, though, even if impractical).

Yes, but I'm really just talking about the idea of doing meaningful
aggregation and simplification.

> > So what we want is something that can intelligently handle delegation
> > in an automatic fashion, which probably includes configurable settings
> > to request/register delegations upstream, and to accept/manage them
> > downstream.  There's no reason that this shouldn't be basic router
> > capabilities.
> 
> For the home router, I believe that this is mandatory if we wish to 
> continue to allow self configuring networks for home users.

Oh, yeah, let me say:  I am assuming that it *is* mandatory that we come
to a solution of some sort.  It may not need to be day 1, but it ought
to be.

> A little 
> extended logic and it can also be useful in larger networks, possibly 
> even to the point of an enterprise network able to completely number 
> itself (including renumbering itself as necessary).

A little pie in the sky, but I *want* to see that as an option.

Not to trivialize Real Network Engineers(tm), but not everything has to
be super complicated.  I would like to see IPv6 reach a point where a
mildly clueful person could plug in a "workgroup switch" into a managed
corporate network, maybe even a few of them daisy-chained, and run a 
little web setup GUI that allows some basic network setup in fairly 
abstract terms, such as setting up a "protected" printer network that
was only accessible to certain parties.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
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With 24 million small businesses in the US alone, that's way too many apples.