North American Network Operators Group

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Re: Notes from the October NANOG meeting

  • From: Mark Knopper
  • Date: Wed Oct 26 23:06:28 1994

  It is very helpful to have these notes from the meeting. Thanks. --Mark

At 11:22 PM 10/25/94, Stan Barber wrote:
>Here are my notes from the recent NANOG meeting. Please note that any
>mistakes are mine. Corrections, providing missing information, or futher
>exposition of
>any of the information here will be gratefully accepted and added to this
>document which will be available via anonymous ftp later this month.
>Notes by Stan Barber <[email protected]>
>[Please note that any errors are mine, and I'd appreciate corrections being
>forwarded to me.]
>Elise Gerich opened the meeting with Merit's current understanding of the
>state of the transition. THENET, CERFNET and MICHNET have expressed
>specific dates for transition.
>John Scudder then discussed some modelling he and Sue Hares have done on
>the projected load at the NAPs. The basic conclusions are that the FDDI
>technology (at Sprint) will be saturated sometime next year and that
>load-balancing strategies among NSPs across the NAPS is imperative for the
>long term viability of the new architecture. John also expressed concern
>over the lack of expressed policy for the collection of statistical data by
>the NAP operators. All of the NAP operator are present and stated that they
>will collect data, but that there are serious and open questions concerning
>the privacy of that data and how to publish it appropriately. John said
>that collecting the data was most important. Without the data, there is no
>source information from which publication become possible. He said that
>MERIT/NSFNET had already tackled these issues. Maybe the NAP operators can
>use this previous work as a model to develop their own policies for
>After the break, Paul Vixie discussed the current status of the DNS and
>BIND.  Specifically, he discusses DNS security. There are two reasons why
>DNS are not secure. There are two papers on this topic and they are both in
>the current BIND kit.  So the information is freely available.
>Consider the case of telnetting across the Internet and getting what
>appears to be your machine's login banner. Doing a double check
>(host->address, then address->host) will help eliminate this problem.
>hosts.equiv and .rhosts are also sources of problems. Polluting the cache
>is a real problem. Doing UDP flooding is another problem. CERT says that
>doing rlogin is bad, but that does not solve the cache pollution problem.
>How to defend?
>1. Validate the packets returned in a response to the query. Routers should
>drop UDP packets on which the source address don't match what it should be.
>(e.g. a udp packet comes in on a WAN link that should have come in via an
>ethernet interface).
>2. There are a number of static validations of packet format that can be
>done. Adding some kind of cryptographic information to the DNS would help.
>Unfortunately, this moves very slowly because there are a number of strong
>conflicting opinions.
>What is being done?
>The current BETA of  BIND has almost everything fixed that can be fixed
>without a new protocol.  Versions prior 4.9 are no longer supported.
>Paul is funded half-time by the Internet Software Consortium. Rick Adams
>funds it via UUNET's non-profit side.  Rick did not want to put it under
>DNS version 2 is being discussed. This is due to the limit in the size of
>the udp packet.  Paul M. and Paul V. are working to say something about
>this at the next IETF.
>HP, Sun, DEC and SGI are working with Paul to adopt the 4.9.3 BIND once it
>is productional.
>After this comes out, Paul will start working on other problems. One
>problem is the size of BIND in core. This change will include using the
>Berkeley db routing to feed this from a disk-based database.
>There will also be some effort for helping doing load-balancing better.
>What about service issues? Providing name service is a start.
>DEC and SGI will be shipping BIND 4.9.3 will be shipping it with the next
>Paul has talked to Novell, but noone else....Novell has not been a helpful
>from the non-Unix side.
>RA Project : Merit and ISI with a subcontract with IBM
>ISI does the Route Server Development and the RA Futures
>Merit does the Routing Registry Databases and Network Management
>The Global Routing Registry consists of the RADB, various private routing
>registries, RIPE and APNIC. The RADB will be used to generate route server
>configurations and potentially router configurations.
>1993 -- RIPE 81
>1994 -- PRIDE tools
>April 1994 -- Merit Routing Registry
>September 1994 -- RIPE-181
>October 1994 -- RIPE-181 Software implementation
>November 1994 -- NSP Policy Registrations/Route Server Configurations
>Why use the RADB? Troubleshooting, Connectivity, Stability
>The Route Server by ISI with IBM
>They facilitate routeing information exchange. They don't forward packets.
>There are two at each NAP with one AS number. They provide routing
>selection and distribution on behalf of clients (NSPs). [Replication of
>gated single table use = view] Multiple views to support clients with
>dissimilar route selection and/or distribution policies. BGP4 and BGP4 MIB
>are supported. RS's AS inserted in AS path, MED is passed unmodified (this
>appears controversal).
>The Route Servers are up and running on a testbed and have been tested with
>up to 8 peers and 5 views. Target ship date to 3 NAPS is October 21. The
>fourth will soon follow.
>The Network Management aspect of the RA project uses a Hierarchically
>Distributed Network Management Model. At the NAP, only local NM Traffic,
>externalizes NAP Problems, SNMPv1 and SNMPv2 are supported. OOB Access
>provides seamless PPP backup & console port access. Remote debugging
>enviromnent is identical to local debugging environment.
>The Centralizes Network Management System at Merit polls distributed rovers
>for problems, consolidates the problems into ROC alert screen. It is
>operational on August 1st which is operated by the University of Michigan
>Network Systems at the same location as the previous NSFNET NOC. 24/7 human
>operator coverage.
>Everything should be operational by the end of November.
>Routing Futures -- Route Server decoupling packet forwarding from routing
>inforation exchange, scalability and modularity. For example, explicit
>routing will be supported (with the development of ERP). IPv6 will be
>provided. Doing analysis of RRDB and define a general policy language
>(backward compatible with RIPE 181). Routing policy consistany and
>aggregration will be developed.
>Securing the route servers -- All of the usual standard mechanisms are
>being applied. Single-use passwords.... mac-layer bridges .... etc....How
>do we keep the routes from getting screwed intentionally? Denial of service
>attacks are possible.
>A design document on the route server will be available via the
>There is a serious concern to sychronization of the route servers and the
>routing registries. No solution has been implemented currently. Merit
>believes that will do updates at least once a day.
>Conversion from PRDB to RRDB
>The PRDB is AS 690 specific, NCARs, twice weekly and AUP constrained.
>The RADB has none of these features.
>Migration will occur before April of 1995. The PRDB will be temporarily
>part of the Global Routing Registry during transition.
>Real soon now -- Still send NCAR and it will be entered into PRDB and RRDB.
>Constancy checking will be more automated. Output for AS 690 will be
>compared from both to check consistancy. While this is happening, users
>will do what they always have. [Check for more information.]
>There is alot of concern among the NANOG participants about the correctness
>of all the information in the PRDB. Specifically, there appears to be some
>inaccuracy (homeas) of the information. ESnet has a special concern about
>[[email protected] to fix the missing homeas problem]
>Transition Plan:
>1. Continue submitting NACRs
>2. Start learning RIPE 181
>3. Set/Confirm your AS's Maintainer object for future security
>4. Switch to using Route Templates (in December)
>When it all works --RADB will be source for AS690 configuration, NCARs will
>go away, use local registries
>RADB to generate AS690 on second week of December.
>NACRs to die at the end of that week.
>Proxy Aggregation -- CIDR by Yakov Rekhter
>Assumptions -- Need to match the volume of routing information with the
>available resources, while providing connectivity server -- on a per
>provider basis. Need to match the amount of resource with the utility of
>routing information -- on a per provider basis.
>But what abaout "MORE THRUST?" It's not a good answer. Drives the costs up,
>doesn't help with complexity of operations, eliminates small providers
>Proxy aggregation -- A mechanism to allow aggregation of routing
>information originated by sites that are BGP-4 incapable.
>Proxy aggregation -- problems -- full consensus must exist for it to work.
>Local aggregation -- to reconnect the entity that benefits from the
>aggregation and the party that creates the aggregation. Bilateral
>agreements would control the disposition of doing local aggregation.
>Potential Candidates for Local Aggregation -- Longer prefix in presence of
>a shorter prefix, Adjacent CIDR Blocks, Aggregation over known holes.
>Routing in the presens of Local Aggregation --
>        AS and router that did the aggregation is identified via BGP
>(AGGREGATOR attribute)
>        Should register in RRDB
>Summary -- adding more memory to routers is not an answer
>Regionals should aggregate their own CIDR blocks
>An NSP may do local aggregation and register it in the RRDB.
>Optimal routing and large scale routing are mutually exclusive.
>CIDR is the only known technique to provide scalable routing in the Internet.
>Large Internet and the ability of every site to control its own routing are
>mutually exclusive.
>Sprint Network Reengineering
>T-3 Network with sites in DC, Atlanta, Ft.Worth and Stockton currently.
>Will be expanding to Seattle, Chicago and Sprint NAP in the next several
>months. ICM uses this network for transit from one coast to the other. They
>expect to create a seperate ICM transit network early next year.
>Next NANOG will be at NCAR in February.
>PacBell NAP Status--Frank Liu
>The Switch is a Newbridge 36-150.
>NSFNET/ANS connected via Hayward today.
>MCINET via Hayward today.
>PB Labs via Concord today.
>Sprintlink connected via  SanJose (not yet).
>NETCOM connected via Santa Clara in the next Month.
>APEX Global Information Services (based in Chicago) will connect via Santa
>Clara, but not yet.
>The Packet Clearing House (consortium) for small providers connected via
>Frame Relay to PB NAP. They will connect via one router to the NAP. It is
>being led by Electric City's Chris Allen.
>CIX connections are also in the cloud, but not in the same community yet.
>Testing done by Bellcore and PB.
>[TTCP was used for testing. The data was put up and removed quickly, so I
>did lose some in taking notes.]
>One source (TAXI/Sonet)  -> One sink
>Two Sources (TAXI/Sonet) -> One Sink
>Five Sources (ethernet connected) ->One Sink (ethernet connected)
>Equipment issues -- DSU HSSI Clock mistmatch with the data rate. Sink
>devices does not have enough processing power to deal with large numbers of
>512 byte packets.
>One Source-> One Sink
>MSS         Window            Througput (out of 40Mb/sec)
>4470            51000                   33.6
>4470            25000                   22.33
>Two Source -> One Sink
>4470            18000                   33.17   (.05% cell loss, .04%
>packet restrans)
>1500            51000                   15.41   (.69% cell loss, 2.76%
>packet restrans)
>Maximum througput is 33.6 Mbps for the 1:1 connection.
>Maximum througput will be higher when the DSU HSSI clock and data-rate
>mistmatch is corrected.
>Cell loss rate is low (.02% -- .69%).
>Througput degraded with the TCP window size is greater than 13000 bytes.
>Large switch buffers and router traffic shaping are needed.
>[The results appear to show TCP backing-off strategy engaging.]
>Future Service Plan of the SF-NAP-- Chin Yuan
>Currently, the NAP does best effort with RFC 1490 encapsulation.
>March 1995 -- Variable Bit Rate, Sub-Rate Tariff (4,10,16,25,34 and 40Mbps
>on 51, 100 and 140Mbps on OC3c). At CPE: Static Traffic Shaping and RFC
>1483 and 1577 support [Traffic Shaping to be supported by Cisco later this
>year in API card for both OC3c and T3.]
>June 1995 -- Support for DS1 ATM (DXI and UNI at 128, 384 kbps and 1.4Mbps)
>1996 or later -- Available Bit Rate and SVCs. At CPE: Dynamic Traffic Shaping
>Notes on Variable Bit Rate:
>Sustainable Cell Rate(SCR) and Maximum Burst Size (MBS)---
>          * Traffic Policing
>          * Aggregated SCR is no greater than the line rate
>          * MBS = 32, 100, 200 cells (Negotiable if > 200 cells)
>Peak Cell Rate (possible)
>          * PCR <=line rate
>Traffic shaping will be required for the more advanced services. Available
>Bit Rate will require feedback to the router.
>ANS on performance --- Curtis Vallamizar
>There are two problems: aggregation of lower-speed TCP flows, support for
>high speed elastic supercomputer application.
>RFC 1191 is very important as is RFC-1323 for these problems to be addressed.
>The work that was done -- previous work showed that top speed for TCP was
>The new work -- TCP Single Flow, TCP Multiple Flow
>Environment -- two different DS3 paths  (NY->MICH: 20msec; NY->TEXAS->MICH:
>68msec), four different versions of the RS6000 router software and Indy/SCs
>Conditions -- Two backround conditions (no backround traffic, reverse TCP
>flow intended to achive 70-80% utilization)
>Differing numbers of TCP flows.
>Results are available on-line via http.  Temporarily it is located at:
>It will be on line more permanently.
>ATM -- What Tim Salo wants from ATM....
>[I ran out of alertness, so I apologize to Tim for having extremely sketchy
>notes on this talk.]
>MAGIC -- Gigabit TestBed
>Currently  Local Area ATM switches over SONET. Mostly FORE switches.
>Lan encapsuation (ATM Forum) versus RFC 1537
>Stan Barber                                                     [email protected]

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