2005-1, good or bad? [Was: Re: Shim6 vs PI addressing]

Andre Oppermann nanog-list at nrg4u.com
Thu Mar 2 20:42:49 UTC 2006

Marshall Eubanks wrote:
> Does this mean that you support 2005-1, or do you think a new ARIN  
> proposal is needed ?

What I'm saying is that we should reconsider parts of IPv6' design
decisions and fix stuff while we can.  Opening the floodgates right
now, which 2005-1 will do, will only cement the current IPv4 way of
doing things with longest-prefix match.  Doing longest-prefix match
for high pps rates and high prefix counts in hardware is complex and
expensive.  Way more so than doing perfect match on 32 bits (giving
4bn routeable slots).

To answer your question: I do support the rationale behind 2005-1
to allow for PI address space according to current IPv4 rules but
I think it is premature right now to make the decision in this way.
Once the first /48 according to it went out we have to support and
carry it forever in the DFZ.  Right now I'm against 2005-1.

We should take a hard look at the current customer requirements and
market drivers and look at either adjustments to current policies or
even certain changes to IPv6 itself to align them.

IMHO we have to find the best cross-section satisfying the following

  ) PI space to avoid renumbering when switching ISP's  (independence)

  ) PI space to multi-home with two or more ISP's  (performance/redundancy)

  ) PA space for ISP's to hand out to single-homed customers/consumers

  ) Efficient and cost-effective implementation of DFZ packet forwarding

I'm a strong supporter of the original layered approach where different
functionality resides on different levels of the stack and is not or
only to least possible extent intermixed.  Putting routing decisions
into the transport layer (4) as it is done or proposed with SCTP and
SHIM6 is Total Evilness(tm) in my book.  Topology and such should be
of no concern to transport.  The network layer (3) must handle that
in a transparent and independent fashion.  This allows for future
changes and improvements without having to change everything everywhere.
And to make it clear I'm totally against geo-addressing finer than the
size of RIR regions.

Why should anyone take me seriously?  Well, I'm running a genuine 4-digit
AS number for as long as the RIR assigned it to me amost a decade ago.
And I'm an operating system developer (FreeBSD) working on the network stack.
This way I can claim to see all sides of the dice which helps a lot for the
Big Picture(tm).


> Regards
> Marshall Eubanks
> On Mar 2, 2006, at 4:28 AM, Andre Oppermann wrote:
>> Owen DeLong wrote:
>>>> Please don't mix up addressing and routing. "PI addressing" as you
>>>> mention is addressing. SHIM6 will become a routing trick.
>>> I think that is overly pessimistic.  I would say that SHIM6 _MAY_
>>> become a routing trick, but, so far, SHIM6 is a still-born piece
>>> of overly complicated vaporware of minimal operational value, if any.
>>> Personally, I think a better solution is to stop overloading IDR
>>> meaning onto IP addresses and use ASNs for IDR and prefixes for
>>> intradomain routing only.
>> Full ACK!  For the IDR we then can use perfect match lookups which
>> scale very well and pretty cheaply to many millions of table entries.
>> BGP scales very well too if you've got a decent cpu in your router.
>> Our OpenBGPD easily does 30 flapping constandly full-feeds with 1  
>> million
>> routes each.
>> Lets get pragmatic and realistic!
>> -- 
>> Andre

More information about the NANOG mailing list