Why does Sprint have address filters again?

Michael Dillon michael at memra.com
Thu May 28 01:58:11 UTC 1998

On Wed, 27 May 1998, Karl Denninger wrote:

> It is also fascinating that Sprint's argument for their filtering (per their
> web page) is that ARIN has espoused this as a "proper" thing to do.  They 
> even provide a web reference to ARIN's statements in this matter.

As an ARIN AC member I'd like to see ARIN send them a note requesting that
they remove this historical revisionism from their website.

> I have to ask what in the dickens ARIN thinks it is doing advocating *policy*
> on address filtering for ISPs,

As far as I know, ARIN is doing no such thing. Seems to me we have here a
document that could have been worded better and probably would have been
worded better if anyone had cared to comment on it.

> [This is a request as an ARIN AC member, who has tried to get a lot of 
> these kinds of questions answered from officers and trustees of ARIN]

Seems to me that you are an AC member that has demanded ARIN provide a lot
more public documentation of its policies and are, no doubt, a prime
motivator for the production of the document in question.

Personally, I think this could have been better handled by sending some
suggestions on wording directly to the author of the document rather than
raising a big public fuss about it. I would suggest that the section in
question be replaced with this:

     In the past, major transit providers have claimed that technical and
     implementation constraints on the Internet routing system cause them
     to enforce various policies in order to reduce the number of globally
     advertised routes and preven the possibility of routing overload. 
     Typically we see these providers setting limits on the size of
     Classless Inter-Domain Routing (CIDR)  prefixes added to the routing
     tables or filtering of non-aggregated routes.

     To aid in the efficient deployment of CIDR, ISPs are encouraged to
     request address space from their upstream provider. The upstream
     provider is to maintain control of the allocated block unless
     explicitly and contractually stated otherwise.

     In an effort to ensure that CIDR is implemented and utilized as
     efficiently as possible, ARIN issues blocks of addresses
     on appropriate "CIDR-supported" bit boundaries. Determination of IP
     address space allocation size is the responsibility of ARIN.

I haven't taken the time to review the rest of the document so if anyone
else has suggestions on revising the wording, I would appreciate it if you
would contact the author directly.

And I think some thanks are in order for the ARIN staff who are
undertaking this thankless task of getting the whole IP allocation
function better documented for all of us. I can't think of a worse
attitude to take than telling them that they are damned if they do and
damned if they don't.

Michael Dillon                 -               Internet & ISP Consulting
Memra Communications Inc.      -               E-mail: michael at memra.com
http://www.memra.com           -  *check out the new name & new website*

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