Subject: mrouted: is having 21155 routes normal?

From: Malcolm Beattie <[email-masked]>
Date: Thu, 1 Aug 1996 14:36:25 +0100 (BST)

I've been running mrouted for a week or too now, tunnelling from
the main Oxford University mrouted to my desktop Linux box.
The number of routes (from using SIGUSR1 and looking in mrouted.dump)
started at about 3000 and is now 21155. This could explain why my
PC (a 486/66DX2 with 16Mb memory) has been really rather slow over
the last couple of days, given that I also use it for day to day work.
Is 21155 routes normal or has something gone mad and injected lots of
bad routes in there? Is there anything I can do to fix it?

--Malcolm

-- 
Malcolm Beattie <[email-masked]>
Unix Systems Programmer
Oxford University Computing Services

---

From: Bill Fenner <[email-masked]>
Date: Thu, 1 Aug 1996 09:16:16 PDT

>bad routes in there? Is there anything I can do to fix it?

Something has gone mad.  It's easy to mis-configure Cisco's DVMRP/PIM
interoperability to inject your entire unicast routing table.

The way I tracked this down last time was by creating a histogram of
the metrics in the routing table, with something like

awk '{print $3}' /usr/tmp/mrouted.dump | sort -n | uniq -c | sort -n

and then find the most common metric (there will probably be like 10K of
them) and run "mtrace" towards a bunch of routes with that metric.  If
all the mtraces end at the same Cisco then you've found the culprit and
can send email (to mbone list or to the contact for the domain) asking them
to stop.

  Bill

---

From: Dino Farinacci <[email-masked]>
Date: Thu, 1 Aug 1996 11:45:06 -0700

>> interoperability to inject your entire unicast routing table.

    After the last time this happened, I said I would put in a limit. I have
    done that. There is an explicit command generated:

	ip dvmrp route-limit 7000

    This will instruct your DVMRP to not inject more than 7000 routes over
    any DVMRP enabled interface/tunnel.

    However, to protect yourself from trashing the MBONE you need to run one
    of the following releases:

	11.0(9.3), 11.1(4.2), 11.2(0.15)

    Take this opportunity to upgrade your cisco multicast routers to one
    of the above releases (or later). It will save you 11th hour antics on 
    Halloween.

Dino

------------------------------------------------------------------------

INTERNET-DRAFT                                              J. Hawkinson
draft-hawkinson-mboned-pruning-00.txt                         BBN Planet
Category: Best Current Practice                             16 July 1996

                     Multicast pruning a necessity

Status of this Memo

   This document specifies an Internet Best Current Practice for the
   Internet Community, and requests discussion and suggestions for
   improvements.  Distribution of this memo is unlimited.

Internet Drafts

   This document is an Internet-Draft.  Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as ``work in progress.''

   To learn the current status of any Internet-Draft, please check the
   ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow
   Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
   munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or
   ftp.isi.edu (US West Coast).

Abstract

   This document mandates that the MBone will be free of non-pruning
   multicast implementations by 31 October 1996.

   It is a product of the Multicast Deployment Working Group in the
   Operational Requirements area of the Internet Engineering Task Force.
   Submit comments to <[email-masked]> or the author.

Discussion

   The MBone (Multicast Backbone) of the Internet is composed of a DVMRP
   backbone connected to regions that may be running other multicast
   routing protocols.

   DVMRP versions prior to 3 do not support pruning. Under such
   versions, multicast datagrams destined for a particular multicast
   group travel to all portions of the network, regardless of the

Hawkinson                                                       [Page 1]

Expires 31 September 1996   INTERNET-DRAFT                  16 July 1996

   presence of members of that group. This behavior is fundamentally
   incompatible with a scalable multicast backbone.

   Effective 31 October 1996, the MBone community will no longer accept
   such non-pruning implementations as a part of the MBone. Such
   implementations should be upgraded or disconnected from the MBone
   prior to that date. Service providers should assist their customers
   in these proceses.

   DVMRP implementations that do not support pruning include mrouted
   versions prior to 3, and Cisco Systems IOS prior to version 11.0(3).
   3Com's NETBuilder routers and LANplex switches have supported pruning
   as long as DVMRP has been available for them (releases 8.3 and 7.0,
   respectively).

   Within non-DVMRP regions, software that does not support DVMRP
   pruning but does support a similar mechanism of a different protocol
   (such as CBT, MOSPF, or PIM) is acceptable, as long as the border
   routers of such a region can translate that mechansism into DVMRP
   pruning.

Security Considerations

   Security considerations are not addresed in this memo.

References

   [IPMULTI] S.E. Deering, "Host extensions for IP multicasting", RFC1054,
           1 May 1988.

   [MREQ] R. Braudes, S. Zabele, "Requirements for Multicast Protocols",
           RFC1458, 26 May 1993.

   [DVMRP-OLD] D. Waitzman, C. Partridge, S.E. Deering, "Distance Vector
           Multicast Routing Protocol", RFC1075, 1 November 1988.

   [DVMRP] T. Pusateri, "Distance Vector Multicast Routing Protocol",
           Work in progress (internet-draft).

Author's Address

   John Hawkinson
   BBN Planet
   150 CambridgePark Drive
   Cambridge, MA 02140

   phone: +1 617 873 3180
   email: [email-masked]

Hawkinson                                                       [Page 2]

---

From: Jimmy Kyriannis <[email-masked]>
Date: Tue, 6 Aug 1996 12:59:00 -0400

What does 11.0(9.3) fix in the original 11.0(9) release?

Jimmy