Current Meeting Report

2.3.14 Prefix Taxonomy Ongoing Measurement & Inter Network Experiment (ptomaine)

NOTE: This charter is a snapshot of the 53rd IETF Meeting in Minneapolis, MN USA. It may now be out-of-date. Last Modified: 11-Feb-02
Mark Knopper <>
Sean Doran <>
Operations and Management Area Director(s):
Randy Bush <>
Bert Wijnen <>
Operations and Management Area Advisor:
Randy Bush <>
Mailing Lists:
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In Body: subscribe ptomaine
Description of Working Group:
Routing table growth has been an issue of much concern. Many have talked about temporary methods to alleviate the drain on Internet resources. In response to these discussions, aggregation and filtering techniques to reduce the amount of routing information carried by routers with global knowledge started to be considered.

The purpose of the Prefix Taxonomy Ongoing Measurement & Inter Network Experiment WG is to consider and measure the problem of routing table growth and possible interim methods for reducing the impact of routing table resource consumption within a network and the global Internet. The first step of the WG is to define the impacts on routing resource consumption and to identify the problems facing routing scalability.

The next step is to develop suggestions for filtering and aggregating prefixes to reduce an individual network's routing table size and route processing load and to suggest possible knobs that result in the least loss of reachability if such methods are determined to be feasible in addressing the problem. This work may possibly define a framework for larger efforts to address the problems facing interdomain routing scalability.


1) To provide a clear definition of the problems facing Internet Routing Scaling today. This includes routing table size and route processing load.

2) To provide a taxonomy to describe prefix information for peer review.

3) To collate measurements of routing table scaling data and publish a reference list.

4) To discuss and document methods of filtering/aggregating prefix information and to discuss and document what support from protocols or vendor knobs that might be helpful in doing this. In addition, to suggest policy guidelines to RIRs, LIRs and/or ISPs for allocations and aggregations,etc. that may be useful.

5) To determine the long and short term effects of filtering/aggregating prefixes to reduce router resource consumption.

6) To develop methods of controlling policy information propagation in order to limit the need for propagation of prefix sub-aggregates.

Some Relevant References: n et/

Goals and Milestones:
Nov 01   Submit Taxonomy Internet-Draft
Dec 01   Submit Problem Statement Internet-Draft
Dec 01   Submit Filtering/Aggregation Internet-Draft
Jan 02   Submit References Internet-Draft
Feb 02   Submit Policy Propagation Internet-Draft
No Current Internet-Drafts

No Request For Comments

Current Meeting Report

PTOMAINE working group
19 March 2002 meeting summary

> - Geoff Huston <>- NOPEER community for BGP route scope control
> draft-huston-nopeer-00.txt

The (3) slides for the draft-huston-nopeer-00.txt proposal can be found at:
or (if you want ppt)

It was agreed to make this a ptomaine wg document.

> - Ted Hardie <> - Bounding Longest Match Considered
> draft-hardie-bounded-longest-match-02.txt

Presentation is at:

Andrew Partan pointed out that there are cases where the announcer
of the covering aggregrate *does not have a route* to the more
specific. This was seen as an anomaly by Ted/Russ, but Andrew,
Geoff, and Randy note that it is very common. This means that the
bounding of the longest match must be constrained to those
announcements where the next hop is common, which limits the utility
of the proposal. It also means that odd other announcements which
have the longer match but different next-hops get preferenced.

Joel Halpern asked a question about BGP communities--whether customers of
ISPs who are supporting the current mechanisms are actually using those
mechanisms. He received a resounding yes.

Cengiz A. pointed out that we need to look at the data. Anyone who has
pointers to relevant data should post to the list.

Andrew: possible persistent route oscillation, as longer prefix may
re-appear somewhere else.

Ted and Russ will consider a plan to test, or at least provide an analytic
proof that this works.

It was agreed to keep discussing this draft in the working group. Ted/Russ
will update to address the points above, and will resubmit.

> - Russ White ( - Controlling the
> redistribution of BGP routes
> draft-bonaventure-bgp-redistribution-02.txt

This is a joint draft with Russ White, Jeffrey Haas, Stefaan De Cnodder and
Bruno Quoitin.

- Requires use of extended communities, which not everyone uses.

- Geoff: how do you know your specifics aren't leaking?

It was agreed to make this a WG document.

> Cathy Wittbrodt <> - presented Gert Doering's presentation on -
IPv6 routing scalability has now everything
as one-GIF-per-Slide format, with mini-HTML around to click previous/next.

This presentation describes the global IPv6 routing table (yes, there is
one...) growth resulting from use of BGP4++ on the combined 6bone and RIR.

- Andrew: The martians (extra long AS path) may not be a BGP withdrawal bug.
They may be a transient state due to BGP counting to infinity. Cathy to ask
Gert about this.

- Can the tunneled v6 AS paths be mapped to real geographic network paths?

Other notes:

- Please comment on WG charter:

- List archive is here:

- Abha's Merit page has been restored (thanks to Merit):


None received.