Subject: ICMP Unreachable Errors in response to multicast

From: Bill Fenner <[email-masked]>
Date: Wed, 19 Nov 1997 09:25:54 PST

As Andrew Patrick said, there's an old problem with Banyan Vines
servers which causes them to respond to multicast with ICMP Network
Unreachable errors.  However, while performing an experiment last week,
I noticed a large number of ICMP errors coming back to me, so collected
some data on them and generated the following table.

After noticing the large percentage of Ciscos running 11.2(8.x) thru
11.2(9), I contacted Cisco and they determined that this appears to be
bug-id CSCdj43447.  This bug affects routers whether multicast routing
is enabled or not; a unicast-only router that simply receives multicast
packets (perhaps because it is on the same subnet as a multicast
router) may still send ICMP errors.  CSCdj43447 is fixed in 11.2(9.1)
and 11.3(0.7), so please upgrade.

If you are responsible for a system on this list, please upgrade it
ASAP, or if you can't upgrade, please remove it from any subnets that
have multicast present.  If you have a system that's on this list but
isn't a Cisco (e.g.  Lantronix and LANCOM and the unidentified
systems), you should contact your product's vendor to get this problem
resolved.

  Bill

IP Address	Unreach	Hostname	Device type
----------	-------	--------	-----------
10.0.1.1	Port	?
128.101.155.254	Host	tc7x.router.umn.edu	cisco 11.2 mrouter
128.102.32.212	Port	nisdn.arc.nasa.gov	cisco Version 11.2(8.5)P mrouter
128.173.188.31	Net	neptune.aoe.vt.edu	AIX Verison 2.2.1
128.252.157.1	Port	?	cisco Version 11.2(9) mrouter
128.39.0.201	Port	trd-gw2.uninett.no	cisco Version 11.2(9) mrouter
128.59.144.1	Port	vortex-gw.net.columbia.edu	cisco 11.2 mrouter
128.63.2.2	Host	gw394.arl.mil	cisco
128.82.254.10	Port	?	cisco 11.2 mrouter
128.82.254.11	Port	?	cisco 11.2 mrouter
128.82.254.12	Port	?	cisco 11.2 mrouter
128.95.1.9	Port	cisco3640.cs.washington.edu	cisco Version 11.2(8.3)P mrouter
129.241.13.1	Host	kjemi-gw.ntnu.no	cisco Version 11.2(9)
129.241.62.1	Host	hb-gw.ntnu.no	cisco Version 11.2(9)P
129.7.1.254	Host	UH2.GW.UH.EDU	cisco
130.111.1.49	Port	gw-orono.caps.maine.edu	cisco 11.2 mrouter
130.202.128.6	Host	milton.ctd.anl.gov	cisco
130.207.244.10	Port	gtri-rtr-fddi.gatech.edu	cisco 11.2 mrouter
130.239.0.59	Port	hum.gw.umu.se	cisco 11.2 mrouter
130.240.22.246	Port	ltu2-s34.luth.se	cisco 11.2 mrouter
130.73.70.112	Host	rout2.zib.de	cisco
130.73.74.112	Host	rout2.zib.de	cisco
131.188.185.100	Net	lancom1.linguistik.uni-erlangen.de	ELSA MicroLink LANCOM
134.130.86.1	Net	wb4.iwwl.RWTH-Aachen.DE
134.130.86.2	Net	wb5.iwwl.RWTH-Aachen.DE
134.130.86.5	Net	wb3.iwwl.RWTH-Aachen.DE
134.193.21.6	Port	?	cisco 11.2 mrouter
134.193.21.7	Port	?	cisco 11.2 mrouter
134.193.210.247	Port	blsgate.umkc.edu	cisco 11.2 mrouter
134.193.210.248	Port	medgate.umkc.edu	cisco 11.2 mrouter
134.193.210.249	Port	adgate.umkc.edu	cisco 11.2 mrouter
134.193.210.251	Port	mnlgate.umkc.edu	cisco 11.2 mrouter
134.193.210.252	Port	ssbgate.umkc.edu	cisco 11.2 mrouter
134.193.210.254	Port	chgate.umkc.edu	cisco 11.2 mrouter
134.193.213.11	Port	dialup1.umkc.edu	cisco 11.2 mrouter
134.193.219.1	Port	dialup2.umkc.edu	cisco 11.2 mrouter
134.2.170.200	Host	tatts5.tat.physik.uni-tuebingen.de	Lantronix ETS16 Version V2.2/28(930223)
134.2.170.201	Host	tatts3.tat.physik.uni-tuebingen.de	LANTRONIX ETS8 Version V2.2/28(930223)
134.55.23.67	Port	esnet2-es-fddi2.es.net	cisco 11.2 mrouter
141.20.1.64	Host	HUgate2-wsbb.rz.hu-berlin.de	cisco 11.2
141.210.1.2	Host	cisco.oakland.edu	cisco Version 11.2(9)P
142.92.36.75	Net	dgbt.banyan.doc.ca	Banyan Vines
142.92.39.26	Net	banyan.dgim.doc.ca	Banyan Vines
150.159.224.4	Port	lci-dmz4.lci.net
150.159.224.5	Host	as5200-1.lci.Net
150.199.76.130	Port	?	cisco 11.2 mrouter
150.199.76.98	Port	?	cisco 11.2 mrouter
155.54.17.205	Net	um400-1.um.es
158.43.137.198	Port	ser0.gw.dicky.pipex.net	cisco 11.2 mrouter
161.55.168.32	Host	rsm-01.pmel.noaa.gov
161.55.64.5	Port	sparrow-dmz.pmel.noaa.gov	cisco 11.1 mrouter
166.48.181.254	Port	ucla-internet-t-3.Bloomington.mci.net	cisco 11.2 mrouter
172.16.199.2	Port	?
192.121.158.98	Port	raa-main.ten34.ces.net	cisco 11.2 mrouter
192.138.85.71	Port	?
192.203.230.243	Port	FIXW-MBONE.NSN.NASA.GOV	cisco Version 11.2(8.4)P mrouter
192.35.217.18	Host	bgty2.ucop.edu	cisco
192.41.177.67	Host	mae-east-fddi1.servint.Net	cisco
193.225.12.8	Host	vhk.iif.hu	cisco
193.54.185.123	Port	r-imag.grenet.fr	cisco Version 11.2(9) mrouter
193.6.206.110	Port	atm-vc-7-33.bme.iif.hu	cisco 11.2 mrouter
193.6.206.81	Port	atm-vc-6-43.vha.iif.hu	cisco 11.2 mrouter
193.84.48.85	Port	?	cisco 11.2 mrouter
194.108.3.133	Port	atmfelk.pasnet.cz	cisco Version 11.2(9)
195.178.64.152	Port	?	cisco 11.2 mrouter
195.206.64.162	Port	?	cisco Version 11.3(0.5)ED mrouter
199.77.150.193	Port	rta-rtr.csc.gatech.edu	cisco 11.2 mrouter
199.77.160.1	Port	campus4-rtr.gatech.edu	cisco 11.2 mrouter
199.94.193.90	Port	maine.bbnplanet.net	cisco 11.2 mrouter
204.162.119.242	Port	demo-router-grey-et0.precept.com	cisco
204.174.218.70	Port	?	cisco 11.2 mrouter
204.30.134.3	Port	?
205.184.205.71	Port	?	cisco 11.2 mrouter
205.189.32.157	Port	?
205.213.126.17	Port	?	cisco Version 11.2(9)P mrouter
207.126.96.46	Port	tch-above-gw.above.net	cisco 11.2 mrouter
207.170.70.129	Host	neuromancer.fc.Net	cisco
208.208.161.126	Port	nboc-dater.smatnet.net	cisco 11.2 mrouter

---

From: Stephen Casner <[email-masked]>
Date: Wed, 19 Nov 1997 10:52:28 -0800 ()

On Wed, 19 Nov 1997, Bill Fenner wrote:
> However, while performing an experiment last week,
...
> 204.162.119.242	Port	demo-router-grey-et0.precept.com	cisco

Ahem, I see my organization is on the bad list -- I plan to get our
routers upgraded ASAP.  In fact, we discovered a different but related
ICMP problem with our ciscos on Monday.  What we found was that they
were sending ICMP TTL exceeded messages when packets were sent with
small TTLs.  I was told that the same bugfix should apply to both
types of ICMPs.

[As we discussed on this list some time back, one should not use
limited TTL to restrict the scope of multicast transmissions except
in an expanding-ring-search mode because the point where the TTL
expires acts as a non-pruning sink.  However, using TTL 1 is always
a valid mechanism for keeping traffic to the local subnet, and that's
what we were doing when we saw the ICMP TTL exceeded messages.]

							-- Steve

---

From: Bill Fenner <[email-masked]>
Date: Wed, 19 Nov 1997 11:27:23 PST

Bill Fenner <[email-masked]> wrote:
>I ... collected

Re-reading my message, I realize that I forgot to credit Mark Handley
with at least half the work of generating the table.  Sorry, Mark!

  Bill