draft minutes of the WG session at RIPE 25

 Here are the draft minutes of the WG session at RIPE 25. Thanks to
 Mike Norris for taking them.
 Comments to the draft minutes are welcome, the final version will
 be circulated next week.
    Joachim

------

		 RIPE 25, Amsterdam 
		Routing Working Group
	Report of Meeting, 23rd September 1996



1.  Opening and Administrivia
    Willem van der Scheun, Chairman, presided and welcomed people
    to the meeting.  There were 89 attenders.  Mike Norris took
    minutes.


2.  Agenda bashing
    A draft agenda of business, circulated by the Chairman in the
    previous week, was agreed.


3.  Chairman of the Routing WG
    Willem announced that his day job prevented him from devoting
    the time necessary to chairmanship of the WG and that he was
    standing down.  He was pleased to say that Joachim Schmitz would
    accept his proposal to be Chairman, and this proposal was
    endorsed by the meeting.  Members thanked Willem for his work
    as Chairman and guidance of the WG.  Joachim chaired the 
    remainder of the meeting.


4.  Report from the RIPE NCC
    Daniel Karrenberg said that the RIPE NCC planned to resume its
    studies of route aggregation.  An exercise he had conducted
    earlier in 1996 and reported to RIPE 24 had revealed plenty
    of room for improvement.  Individual reports to those responsible
    for over-specific routing had resulted in significant improvements.
    Since then, however, the aggregation situation had disimproved.
    Daniel's impression was that some ISPs didn't care or wouldn't
    take the trouble to correct matters.  

    Further remedial action was needed and the Contributors' Committee
    supported the NCC in this work.  Skilled staff would soon be 
    appointed and they would help ISPs in promoting route aggregation.
    While neither RIPE nor the NCC could take action against any
    offenders, the use of peer pressure among the ISPs could be
    used in a positive manner to improve the position.

    The meeting encouraged ISPs to supply BGP data to the NCC on
    request for the purpose of analysing route aggregation.  

    New Action: the NCC would report on route aggregation at RIPE 26.


5.  Working Experience with Route Object Editor (ROE)
    ftp://ftp.ripe.net/ripe/presentations/ripe-m25-jschmitz-work-exp-roe.html

    Joachim Schmitz reported on his experience with ROE.  This was
    part of the RA Toolset and had been written by Cengiz 
    Alaettinoglu.  Its purpose was to view and manipulate route
    objects and to compare them with operational routes.  It worked
    on routes as objects from Internet routing registries (IRRs)
    and as determined from routers (by means of input BGP tables).

    Compiled with C++ in a Tcl/Tk environment, ROE was easy to 
    instal.  With its GUI it was easy to use.  As not all IRRs
    were aligned in the way they worked, ROE displayed separate
    route registrations where appropriate.

    Joachim found it slow in operation, although Cengiz later
    indicated that this was probably due to network and server
    performance and not to the ROE program execution.  It was
    also not clear to Joachim whether live or mirrored IRR data
    was used.

    He suggested that the program could be improved by allowing
    more configuration options and greater clarity in some of the 
    messages.  This and other feedback should be directed to 
    Cengiz.

    Overall, he recommended ROE for operational use, particularly
    for complex routing tasks.


6.  Progressive BGP route flap dampening
    ftp://ftp.ripe.net/ripe/presentations/ripe-m25-tbarber-bgp-damp.html

    Tony Barber gave a presentation on the strategies used by
    UUnet-Pipex to reduce the effects of route flapping and to
    try to prevent router table overflow.  These were:

	- route dampening
	- prefix filtering
	- more router memory

    They had encountered many instabilities from peers and found
    that many ISPs had not deployed CIDR; this gave rise to more
    flapping as more routes, and particularly more specific ones,
    were advertised.

    Tony explained the parameters used for route dampening on a
    Cisco router.  He had arrived at the following re-use times
    for various route sizes:

	/24 and greater		~160 minutes
	/23 and /22		~60 minutes
	/21 and less		~30 minutes

    He recommended filtering out all prefixes more specific than /24.

    While route dampening consumed router memory, this was more or
    less balanced by a reduction in routing CPU cycles.

    He recommended that if route dampening was to be widely
    deployed in Europe, consistency was important.  In this sense,
    the Routing WG should agree on guidelines for parameters to 
    be used.

    In discussion, the following points were made:

	- aggregation works in reducing router load and route
	  flapping.

	- route flapping is often a feature of certain autonomous
	  systems rather than a function of prefix length.

	- much instability was due to configuration changes and
	  errors as distinct from link failures.

	- making dampening dependent on prefix length could
	  penalise many stable /24s.

	- it might be useful to discriminate against /24s in the 
	  192.0.0.0/8 block (the swamp).

	- the focus should be on keeping noise out of the system
	  rather than trying to mitigate against it once in the
	  system.

    In summary, it was agreed that route dampening was an
    important topic and that more discussion was needed.


7.  Routing Policy analysis tools
    http://www.isi.edu/ra/Presentations

    Cengiz Alaettinoglu of ISI presented a review of recent 
    developments and updates in the RA toolset, now at version
    3.4.0.

    The set of front-end tools used a number of back-end libraries,
    which made program development easier.  It required RAWhoisd
    v3.0 and had been ported to several operating systems.  Cengiz
    gave details of availability (URL = http://www.isi.edu/ra/RAToolSet
    as official reference or copies also available from
    ftp://ftp.isi.edu/pub/cengiz/RAToolSet-3.4.0.tar.gz or
    ftp://ftp.ra.net/routing.arbiter/tools/RAToolSet/RAToolSet-3.4.0.tar.gz )
    and of the mailing list (ratoolset@localhost).
    The toolset was made available for demonstration
    purposes to attenders of RIPE 25.

    RtConfig generated the BGP access list part ofrouter 
    configuration from route objects.  It was now used in
    production by some major network operators.

    ROE was again shown, with reference to review options
    before submitting a changed route object.

    The AS object editor (AOE) was not implemented, though it
    was on demo at RIPE 25.

    CIDRAdvisor identifies 'safe' aggregates by route originators
    as well as aggregates for proxies.  Cengiz showed the effects
    of using various radius values for the distance that aggregation
    should hold.


Summary of Actions
------------------
    Action 22.10 on Joachim Schmitz
       To trigger the discussion on the mailing list of the Routing WG,
       which focus to choose for a future tool development project and
       to come to consensus on it
    Action 24.4 on Joachim Schmitz
       To investigate the status of the CIDR FAQ and see whether additions
       are needed, probably by triggering a discussion on the mailing list
    New action on Daniel Karrenberg/RIPE NCC
       To report on the results from the route aggregation analysis on
       the 26th RIPE meeting
    New action on Joachim Schmitz
       To coordinate making the presentations at the Routing WG available


Mike Norris
23/9/96

_____________________________________________________________________________

 Dr. Joachim Schmitz                                   schmitz@localhost
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