nanog mailing list archives

Re: who gets a /32 [Re: IPV6 renumbering painless?]


From: bmanning () vacation karoshi com
Date: Fri, 26 Nov 2004 04:21:38 +0000


Sure, sooner or later two networks will happen to generate the same prefix.
When that happens -- and assuming those networks want to talk to each other,
one of them simply generates a new prefix and renumbers.  This is a
significantly better situation than with RFC1918 (or SLAs) where a collision
is _guaranteed_.

        unmanaged delegations _will_ create collisions.  and the problem
        is not when these sites want to talk w/ each other, its when your
        packets go to  (one) of the other places using the identical
        prefix.

and then there is the nasty delusion of "Internet"...  protestations
to the contrary, the VSNL view of the "Internet" is vastly different
than the US DOD view of the "Internet", is vastly different than the
GE view, is different than the AS 701 view, is different than the
Chinese R&E Network (CERN) view....  which one(s) count?  Policy
routing dictates that there is no such thing as a "global" routing
table...

There are clearly many parts of the Internet that are "private" and one
large part in the middle that is clearly "public".  ULAs are intended to
only be used within the "private" parts or even totally disconnected IP
networks.

        that model -might- have been accurate once, but has not been
        an accurate representation for several years. there is no middle,

 
For me, as long as I have IP reachability to those folks whom I want
or need to talk to, I could care less about the "rest" of the folks
using IP to move datagrams about ...

Exactly.  However, the scope of who you want/need to talk to dictates what
sort of addresses you need (with the current routing architecture) and where
you get them.

        the "scope" of who I want to talk to varies over time.
        just because the list of folks I want to talk to does not
        intersect w/ yours does not give you the right to tell me
        that I must use "private" or ULA or site-local addresses.
        we should each be able to be delegated address space which 
        has -zero- chance of collison w/o a means to arbitrate.

        ULAs have no defined arbitration technique defined, other than
        through the legal system.  RIR managed space has the arbitration
        technique as an intergral component of the delegation process.

        roughly -  ULA == the lawless west
                   RIR == civilized society

        -IF- ula space is ever approved, my advice to all transit providers
        is to never filter it.

S

Stephen Sprunk        "Stupid people surround themselves with smart
CCIE #3723           people.  Smart people surround themselves with
K5SSS         smart people who disagree with them."  --Aaron Sorkin



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