draft-ietf-mboned-mdh-01.txt   draft-ietf-mboned-mdh-02.txt 
MBONE Deployment Working Group Dave Thaler MBONE Deployment Working Group Dave Thaler
INTERNET-DRAFT Microsoft INTERNET-DRAFT Microsoft
Category: Informational Bernard Aboba Category: Informational Bernard Aboba
<draft-ietf-mboned-mdh-01.txt> Microsoft <draft-ietf-mboned-mdh-02.txt> Microsoft
14 October 1998 12 August 1999
Multicast Debugging Handbook Multicast Debugging Handbook
1. Status of this Memo 1. Status of this Memo
This document is an Internet-Draft. Internet-Drafts are working docu- This document is an Internet-Draft and is in full conformance with all
ments of the Internet Engineering Task Force (IETF), its areas, and provisions of Section 10 of RFC2026.
its working groups. Note that other groups may also distribute work-
ing documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are working documents of the Internet Engineering Task
and may be updated, replaced, or obsoleted by other documents at any Force (IETF), its areas, and its working groups. Note that other groups
time. It is inappropriate to use Internet-Drafts as reference mate- may also distribute working documents as Internet-Drafts. Internet-
rial or to cite them other than as ``work in progress.'' 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
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To learn the current status of any Internet-Draft, please check the The list of current Internet-Drafts can be accessed at
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ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim).
The distribution of this memo is unlimited. It is filed as <draft- The list of Internet-Draft Shadow Directories can be accessed at
ietf-mboned-mdh-01.txt>, and expires May 1, 1999. Please send com- http://www.ietf.org/shadow.html.
ments to the authors.
2. Abstract The distribution of this memo is unlimited. It is filed as <draft-ietf-
mboned-mdh-02.txt>, and expires March 1, 2000. Please send comments to
the authors.
This document serves as a handbook for the debugging of multicast con- 2. Copyright Notice
nectivity problems. In addition to reviewing commonly encountered
problems, the draft summarizes publicly distributable multicast diag-
nostic tools, and provides examples of their use, along with pointers
to source and binary distributions.
3. Introduction Copyright (C) The Internet Society (1999). All Rights Reserved.
3. Abstract
This document serves as a handbook for the debugging of multicast
connectivity problems. In addition to reviewing commonly encountered
problems, the draft summarizes publicly distributable multicast
diagnostic tools, and provides examples of their use, along with
pointers to source and binary distributions.
4. Introduction
In order to deploy multicast on a large scale, it is necessary for In order to deploy multicast on a large scale, it is necessary for
Network Operations Centers, support personnel and customers to be able Network Operations Centers, support personnel and customers to be able
to diagnose problems. Over the years a number of tools have been to diagnose problems. Over the years a number of tools have been
developed that can assist in the diagnostic process. This document developed that can assist in the diagnostic process. This document
serves as a handbook for the debugging of multicast connectivity prob- serves as a handbook for the debugging of multicast connectivity
lems. In addition to reviewing commonly encountered problems, the problems. In addition to reviewing commonly encountered problems, the
draft summarizes publicly distributable multicast diagnostic tools,
and provides examples of their use, along with pointers to source and
binary distributions.
4. Usage scenarios draft summarizes publicly distributable multicast diagnostic tools, and
provides examples of their use, along with pointers to source and binary
distributions.
Multicast diagnostic tools are typically employed in one of the fol- 5. Usage scenarios
lowing settings:
Multicast diagnostic tools are typically employed in one of the
following settings:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
| Customer service or | SDR | | Customer service or | SDR |
| support | mtrace | | support | mtrace |
| | RTPmon | | | RTPmon |
| | Dr. Watson | | | Dr. Watson |
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
skipping to change at page 2, line 44 skipping to change at page 2, line 48
| | mrtree | | | mrtree |
| | map-mbone | | | map-mbone |
| Network Operations | MVIEW | | Network Operations | MVIEW |
| Center | Multicast heartbeat | | Center | Multicast heartbeat |
| | mwatch and mcollect | | | mwatch and mcollect |
| | asn | | | asn |
| | asname | | | asname |
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.1. Customer service and support 5.1. Customer service and support
ISPs offering multicast services are likely to encounter the following ISPs offering multicast services are likely to encounter the following
classes of customer questions: classes of customer questions:
Session announcement problems Session announcement problems
Reception problems Reception problems
Multicast router problems Multicast router problems
Below we discuss how each of these types of problems may be diagnosed. Below we discuss how each of these types of problems may be diagnosed.
4.1.1. Session announcement problems 5.1.1. Session announcement problems
Session announcement questions are those which relate to the user's Session announcement questions are those which relate to the user's
session announcement software. Sample complaints include: session announcement software. Sample complaints include:
No conferences were visible in the session announcement tool No conferences were visible in the session announcement tool
Conference X was not visible in the session announcement tool Conference X was not visible in the session announcement tool
I can see conferences when dialed into POPA, but not POPB I can see conferences when dialed into POPA, but not POPB
I can receive conferences listed in SDR, but sometimes when I join I can receive conferences listed in SDR, but sometimes when I join
conferences via a Web site, I cannot receive them. conferences via a Web site, I cannot receive them.
Session announcement questions are typically investigated via the fol- Session announcement questions are typically investigated via the
lowing procedure: following procedure:
1. If only a specific session announcement is missing, check the ses- 1. If only a specific session announcement is missing, check the
sion announcement from somewhere where it is being received, and find session announcement from somewhere where it is being received, and find
the group(s) and ports that the session utilizes, as well as the the group(s) and ports that the session utilizes, as well as the source
source IP addresses. If the problem is with all session announce- IP addresses. If the problem is with all session announcements, find
ments, find the information on any current session announcement which the information on any current session announcement which should be seen
should be seen by the user. by the user.
2. Find out the user's IP address, if known, and the POP dialed into 2. Find out the user's IP address, if known, and the POP dialed into or
or router connected to. One way to determine the user's router given router connected to. One way to determine the user's router given their
their IP address is to mtrace or traceroute to their address. IP address is to mtrace or traceroute to their address.
3. Do an mtrace between the session announcement's origin and the 3. Do an mtrace between the session announcement's origin and the
receiver on the sap.mcast.net group. If the mtrace succeeds, note any receiver on the sap.mcast.net group. If the mtrace succeeds, note any
hops showing loss. hops showing loss.
4. If the mtrace never gets past the receiver itself, check the NASes 4. If the mtrace never gets past the receiver itself, check the NASes
or routers with mstat -l to see if the relevant group has been joined. or routers with mstat -l to see if the relevant group has been joined.
If not, the problem is probably with the receiver's host. Ask the If not, the problem is probably with the receiver's host. Ask the user
user to check with Dr. Watson or a sniffer to see if the router is to check with Dr. Watson or a sniffer to see if the router is sending
sending IGMP membership queries, and if the host is responding with IGMP membership queries, and if the host is responding with membership
membership reports and if so, what versions are being used. reports and if so, what versions are being used.
5. If the sap.mcast.net group has been joined, but the mtrace failed, 5. If the sap.mcast.net group has been joined, but the mtrace failed,
the problem is likely a multicast routing problem (see section 4.1.3). the problem is likely a multicast routing problem (see section 4.1.3).
6. If the mtrace succeeded, and one hop shows 100% loss, compare the 6. If the mtrace succeeded, and one hop shows 100% loss, compare the
output with the TTL of the session announcement. Users may download output with the TTL of the session announcement. Users may download
session descriptions from Web sites that they may not be in the posi- session descriptions from Web sites that they may not be in the position
tion to receive, due to site or regional scoping. The loss may also
be the result of a scoped boundary separating the originator and the
receiver, which will also be indicated as such by mtrace.
7. Otherwise, if the mtrace succeeded, look for hops showing non-neg- to receive, due to site or regional scoping. The loss may also be the
ligible loss. These typically denote points of congestion (see sec- result of a scoped boundary separating the originator and the receiver,
tion 4.3.1). Note that if rate-limiting is installed on these con- which will also be indicated as such by mtrace.
gested links, session announcements are often lost since SAP traffic
7. Otherwise, if the mtrace succeeded, look for hops showing non-
negligible loss. These typically denote points of congestion (see
section 4.3.1). Note that if rate-limiting is installed on these
congested links, session announcements are often lost since SAP traffic
is given lower priority. is given lower priority.
8. If all else fails, request a network sniff from the user, and 8. If all else fails, request a network sniff from the user, and check
check whether it shows traffic to sap.mcast.net, and if so, from what whether it shows traffic to sap.mcast.net, and if so, from what sources,
sources, and what is being announced. and what is being announced.
4.1.2. Reception problems 5.1.2. Reception problems
Reception questions are those where the user has successfully received Reception questions are those where the user has successfully received
the session announcement, but was unable to receive one or more media the session announcement, but was unable to receive one or more media
streams for the session joined. Sample complaints include: streams for the session joined. Sample complaints include:
I joined conference X, but nothing happened I joined conference X, but nothing happened
I joined conference X, got video but no audio I joined conference X, got video but no audio
I joined conference X, and got intermittent audio I joined conference X, and got intermittent audio
I can't see source X, but source X can see me (or vice versa) I can't see source X, but source X can see me (or vice versa)
Reception questions are typically investigated via the following pro- Reception questions are typically investigated via the following
cedure: procedure:
1. Check the session announcement, find the group(s) and ports that 1. Check the session announcement, find the group(s) and ports that the
the session utilizes, as well as the source IP addresses. session utilizes, as well as the source IP addresses.
2. Find out the user's IP address, if known, and the POP dialed into 2. Find out the user's IP address, if known, and the POP dialed into or
or router connected to. One way to determine the user's router given router connected to. One way to determine the user's router given their
their IP address is to mtrace or traceroute to their address. IP address is to mtrace or traceroute to their address.
3. Check if the user is sending RTCP reports with RTPmon, and if so, 3. Check if the user is sending RTCP reports with RTPmon, and if so,
what the loss rate is. what the loss rate is.
4. Do an mtrace between the source and the receiver on the relevant 4. Do an mtrace between the source and the receiver on the relevant
group. If the mtrace succeeds, note any hops showing loss. group. If the mtrace succeeds, note any hops showing loss.
5. If the mtrace never gets past the receiver itself, check the NASes 5. If the mtrace never gets past the receiver itself, check the NASes
or routers with mstat -l to see if the relevant group has been joined. or routers with mstat -l to see if the relevant group has been joined.
If not, the problem is probably with the receiver's host. Check with If not, the problem is probably with the receiver's host. Check with
Dr. Watson to see if the router is sending IGMP membership queries, Dr. Watson to see if the router is sending IGMP membership queries, and
and if the host is responding with membership reports and if so, what if the host is responding with membership reports and if so, what
versions are being used. versions are being used.
6. If the relevant group has been joined, but the mtrace failed, the 6. If the relevant group has been joined, but the mtrace failed, the
problem is likely a multicast routing problem (see section 4.1.3). problem is likely a multicast routing problem (see section 4.1.3).
7. If the mtrace succeeded, and one hop shows 100% loss, compare the 7. If the mtrace succeeded, and one hop shows 100% loss, compare the
output with the TTL of the session announcement. The user may not be output with the TTL of the session announcement. The user may not be in
in a position to receive data from the source, due to site or regional a position to receive data from the source, due to site or regional
scoping. The loss may also be the result of a scoped boundary sepa- scoping. The loss may also be the result of a scoped boundary
rating the source and the receiver, which will also be indicated as separating the source and the receiver, which will also be indicated as
such by mtrace. such by mtrace.
8. Otherwise, if the mtrace succeeded, look for hops showing non-neg- 8. Otherwise, if the mtrace succeeded, look for hops showing non-
ligible loss. These typically denote points of congestion (see sec- negligible loss. These typically denote points of congestion (see
tion 4.3.1). section 4.3.1).
9. If all else fails, request a network sniff from the user, and 9. If all else fails, request a network sniff from the user, and check
check whether it shows traffic to the relevant group, and if so, from whether it shows traffic to the relevant group, and if so, from what
what sources. sources.
Other reception complaints include: Other reception complaints include:
When I join my first conference, it works great. But then when I When I join my first conference, it works great. But then when I quit
quit that and join another one, it doesn't work anymore. that and join another one, it doesn't work anymore.
Why is my modem light is still flashing even after I've quit SDR Why is my modem light is still flashing even after I've quit SDR and
and VIC? VIC?
Such problems are often IGMP-related problems observed by a user con- Such problems are often IGMP-related problems observed by a user
necting to the network using a host which is running a TCP/IP stack connecting to the network using a host which is running a TCP/IP stack
implementing IGMP v1. Such users will experience long leave latencies, implementing IGMP v1. Such users will experience long leave latencies,
with resulting poor reception and/or performance of other applica- with resulting poor reception and/or performance of other applications.
tions. Such problems can be distinguished from ordinary reception Such problems can be distinguished from ordinary reception problems in
problems in that they typically do not occur for the first session that they typically do not occur for the first session joined, only for
joined, only for subsequent sessions. The solution consists of upgrad- subsequent sessions. The solution consists of upgrading the user to an
ing the user to an IGMP v2-capable stack. IGMP v2-capable stack. IGMP is described in [2].
IGMP-related questions are typically investigated by the following IGMP-related questions are typically investigated by the following
procedure: procedure:
1. Obtain the vendor and version of the user's TCP/IP stack. Deter- 1. Obtain the vendor and version of the user's TCP/IP stack. Determine
mine whether this stack is IGMP v2-enabled. whether this stack is IGMP v2-enabled.
2. Ask the user to run Dr. Watson or a network sniffer and to indi- 2. Ask the user to run Dr. Watson or a network sniffer and to indicate
cate whether IGMP queries are being seen, whether responses are being whether IGMP queries are being seen, whether responses are being sent,
sent, and if so, what version. and if so, what version.
4.1.3. Multicast router problems 5.1.3. Multicast router problems
Multicast router questions are those which relate to the setup of a Multicast router questions are those which relate to the setup of a
multicast router. Sample complaints include: multicast router. Sample complaints include:
I can get video and audio when online with ISDN, but not with a I can get video and audio when online with ISDN, but not with a
modem, or vice versa. modem, or vice versa.
I can't bring up a DVMRP tunnel to my site. Why not? I can't bring up a DVMRP tunnel to my site. Why not?
My router works great. Why can't I get multicast? My router works great. Why can't I get multicast?
Why can't I source multicast? Why can't I source multicast?
Multicast routing questions are typically investigated via the follow- Multicast routing questions are typically investigated via the following
ing procedure: procedure:
1. Ask the user what the router vendor is, and what software version 1. Ask the user what the router vendor is, and what software version
they have running. Attempt to verify this information using mrinfo or they have running. Attempt to verify this information using mrinfo or
mstat. mstat.
2. Check whether this vendor and version supports multicast routing, 2. Check whether this vendor and version supports multicast routing, and
and whether an upgrade to a later version is recommended. whether an upgrade to a later version is recommended.
3. Ask for a copy of the router configuration file. 3. Ask for a copy of the router configuration file.
4. Check whether the user has NAT enabled; this is incompatible with 4. Check whether the user has NAT enabled; this is incompatible with
most multicast routing protocols, and so should be switched off. most multicast routing protocols, and so should be switched off.
5. Find out the user's IP address(es), or if not known, the POP dialed 5. Find out the user's IP address(es), or if not known, the POP dialed
into or router connected to. into or router connected to.
6. Check the loss rate and connectivity by doing an mtrace from vari- 6. Check the loss rate and connectivity by doing an mtrace from various
ous sources to the user's IP address. sources to the user's IP address.
7. Check the user's router with mstat -l to see if it has joined any 7. Check the user's router with mstat -l to see if it has joined any
multicast groups, and check upstream routers to see if they are sub- multicast groups, and check upstream routers to see if they are
scribed to any groups. subscribed to any groups.
8. When all else fails, request a network sniff and examine it to 8. When all else fails, request a network sniff and examine it to
determine what multicast routing protocols are being run, if any. determine what multicast routing protocols are being run, if any.
4.2. Network Operations Center 5.2. Network Operations Center
A Network Operations Center (NOC) will typically receive a complaint A Network Operations Center (NOC) will typically receive a complaint
after it has been investigated by customer support and determined to after it has been investigated by customer support and determined to be
be a network-related issue. Although it is desirable for customer sup- a network-related issue. Although it is desirable for customer support
port to have performed the diagnostic tests described above, if this to have performed the diagnostic tests described above, if this has not
has not been done, NOC personnel will need to perform the tests them- been done, NOC personnel will need to perform the tests themselves to
selves to isolate the cause of the problem. If the proper systems have isolate the cause of the problem. If the proper systems have been
been installed, in most cases, the NOC will already have been alerted installed, in most cases, the NOC will already have been alerted to the
to the problem prior to receiving referrals from customer support. The problem prior to receiving referrals from customer support. The
following diagnostic procedures are recommended: following diagnostic procedures are recommended:
1. Regularly generate summaries based on RTCP receiver and sender 1. Regularly generate summaries based on RTCP receiver and sender
reports, using RTP monitoring tools. Sample reports may include aver- reports, using RTP monitoring tools. Sample reports may include average
age loss rates experienced during sessions, or users whose loss rates loss rates experienced during sessions, or users whose loss rates exceed
exceed a particular threshold. a particular threshold.
2. Determine the source of the problems by doing mtraces between the 2. Determine the source of the problems by doing mtraces between the
sources and the receivers. sources and the receivers.
3. On a network monitoring station, keep track of the functioning of 3. On a network monitoring station, keep track of the functioning of
multicast-enabled hardware, either by doing periodic mtraces, or by multicast-enabled hardware, either by doing periodic mtraces, or by
using a heartbeat monitor to receive SNMP traps from equipment losing using a heartbeat monitor to receive SNMP traps from equipment losing
the heartbeat. the heartbeat.
4. In order to keep track of group topologies, use mapping tools such 4. In order to keep track of group topologies, use mapping tools such as
as map-mbone, MVIEW, or mrtree, along with autonomous system mapping map-mbone, MVIEW, or mrtree, along with autonomous system mapping tools
tools such as asn and asname. such as asn and asname.
4.3. Network or system administrator 5.3. Network or system administrator
The NOC will escalate network engineering problems to network engi- The NOC will escalate network engineering problems to network engineers
neers and system administrators if their intervention is required. In and system administrators if their intervention is required. In order to
order to understand the origin of the problem and repair it, it is understand the origin of the problem and repair it, it is necessary to
necessary to diagnose the operations of individual systems and routers diagnose the operations of individual systems and routers using router
using router and system diagnostics such as netstat, mrinfo, mstat, and system diagnostics such as netstat, mrinfo, mstat, mconfig, RTPmon,
mconfig, RTPmon, and mtrace, as well as network analysis tools such as and mtrace, as well as network analysis tools such as tcpdump or Dr.
tcpdump or Dr. Watson. Watson.
In smaller installations the network engineer or system administrator In smaller installations the network engineer or system administrator
often doubles as customer support and network operations guru, in often doubles as customer support and network operations guru, in which
which case problems may be escalated without any triage (our condo- case problems may be escalated without any triage (our condolences).
lences).
Typical classes of problems encountered by network engineers and sys- Typical classes of problems encountered by network engineers and system
tem administrators include: administrators include:
Congestion and rate-limiting problems Congestion and rate-limiting problems
Multicast routing problems Multicast routing problems
4.3.1. Congestion and rate limiting problems 5.3.1. Congestion and rate limiting problems
Congestion and rate limiting problems result in high packet loss with Congestion and rate limiting problems result in high packet loss with
subsequent loss of session announcements and decrease in quality of subsequent loss of session announcements and decrease in quality of
audio and video. These problems may be investigated via the following audio and video. These problems may be investigated via the following
procedure: procedure:
1. Use RTPmon to check for receivers experiencing packet loss. 1. Use RTPmon to check for receivers experiencing packet loss.
2. Do an mtrace from the source to the receiver on the relevant group 2. Do an mtrace from the source to the receiver on the relevant group in
in order to locate the problematic hops. order to locate the problematic hops.
3. Do an mtrace in the opposite direction to help distinguish whether 3. Do an mtrace in the opposite direction to help distinguish whether
the problem is with the router or the link at that hop. the problem is with the router or the link at that hop.
4. If the reverse mtrace shows similar loss at an hop adjacent to the 4. If the reverse mtrace shows similar loss at an hop adjacent to the
lossy hop in the forward mtrace, odds are that the intermediate router lossy hop in the forward mtrace, odds are that the intermediate router
is overloaded. Use mrinfo to check the fanout on the router. Over- is overloaded. Use mrinfo to check the fanout on the router.
loaded routers are often the result of having too many tunnels. Overloaded routers are often the result of having too many tunnels.
5. If the reverse mtrace shows no problems near that hop, indicating 5. If the reverse mtrace shows no problems near that hop, indicating
that loss is one-way, then check the router on the upstream end of the that loss is one-way, then check the router on the upstream end of the
link with mstat -nv to see if it has a rate-limit set on the link, and link with mstat -nv to see if it has a rate-limit set on the link, and
if the link traffic is near that limit. if the link traffic is near that limit.
6. If the reverse mtrace shows loss over the same link, the problem is 6. If the reverse mtrace shows loss over the same link, the problem is
likely to be link congestion. Use mstat -nv to see how much bandwidth likely to be link congestion. Use mstat -nv to see how much bandwidth
is being used by multicast traffic. (If mstat fails, running an is being used by multicast traffic. (If mstat fails, running an mtrace
mtrace with the -T option may help to confirm link congestion, with the -T option may help to confirm link congestion, although the
although the statistics can be misleading.) statistics can be misleading.)
7. If a congested link is suspected, but mstat failed, another indica- 7. If a congested link is suspected, but mstat failed, another indicator
tor can be obtained by doing an mtrace from the session announcer to can be obtained by doing an mtrace from the session announcer to the
the destination on other groups joined by the receiver, such as the destination on other groups joined by the receiver, such as the SAP
SAP group, and comparing loss statistics. group, and comparing loss statistics.
8. Check for unicast packet loss over the link using ping. Multicast 8. Check for unicast packet loss over the link using ping. Multicast
(but not unicast) packet loss on a link with a rate limit is an indi- (but not unicast) packet loss on a link with a rate limit is an
cation that the link's multicast rate limit should be raised or elimi- indication that the link's multicast rate limit should be raised or
nated entirely. Packet loss on a link without rate limiting is an eliminated entirely. Packet loss on a link without rate limiting is an
indication of congestion. On such links it may be desirable to add a indication of congestion. On such links it may be desirable to add a
rate limit. Since DVMRP prunes are currently not retransmitted by most rate limit. Since DVMRP prunes are currently not retransmitted by most
routers, prunes may be lost if no rate limit exists, which may further routers, prunes may be lost if no rate limit exists, which may further
worsen the congestion problem. worsen the congestion problem.
9. Use mstat -gR to see whether a single group is using an inordinate 9. Use mstat -gR to see whether a single group is using an inordinate
amount of the link bandwidth. If so, use mstat to see whether a sin- amount of the link bandwidth. If so, use mstat to see whether a single
gle source to that group is using an inordinate amount of the link source to that group is using an inordinate amount of the link
bandwidth. If so, attempt to contact the source (contact information bandwidth. If so, attempt to contact the source (contact information
may be available in the session announcement). may be available in the session announcement).
4.3.2. Multicast routing problems 5.3.2. Multicast routing problems
Multicast routing problems include: Multicast routing problems include:
Duplicate packets Duplicate packets
Injection of bogus routes (typically into DVMRP) Injection of bogus routes (typically into DVMRP)
Redistribution of unicast routes (via BGP or an IGP) into DVMRP Redistribution of unicast routes (via BGP or an IGP) into DVMRP
Non-pruning routers Non-pruning routers
Duplicate packets are a symptom of routing loops. This problem may be Duplicate packets are a symptom of routing loops. This problem may be
investigated via the following procedure: investigated via the following procedure:
1. Use a program such as Duppkts to detect duplicate packets. 1. Use a program such as Duppkts to detect duplicate packets.
2. Use a network monitor or RTPmon to find the sources and receivers 2. Use a network monitor or RTPmon to find the sources and receivers on
on the group. the group.
3. Do an mtrace from the source(s) to the receivers in order to find 3. Do an mtrace from the source(s) to the receivers in order to find
the loop. Duplicates will also show up in mtrace output as hops with the loop. Duplicates will also show up in mtrace output as hops with
negative loss. negative loss.
Bogus route injection problems may be investigated via the following Bogus route injection problems may be investigated via the following
procedure: procedure:
1. Dump the DVMRP routing table. The routing table may be examined 1. Dump the DVMRP routing table. The routing table may be examined
remotely via mstat using the -r options, or locally (for mrouted) by remotely via mstat using the -r options, or locally (for mrouted) by
sending the USR1 signal to mrouted, generating the sending the USR1 signal to mrouted, generating the /var/tmp/mrouted.dump
/var/tmp/mrouted.dump file. file.
2. Check the table for bogus routes (known as "martians"). Bogus 2. Check the table for bogus routes (known as "martians"). Bogus routes
routes include addresses reserved for use by private internets, as include addresses reserved for use by private internets, as described in
described in [9]. These routes include 10/8, 172.16/12, or 192.168/16, [9]. These routes include 10/8, 172.16/12, or 192.168/16, or more
or more specific routes within these regions. Injecting a default specific routes within these regions. Injecting a default route into
route into the DVMRP backbone is also considered to be a bogus route. the DVMRP backbone is also considered to be a bogus route.
3. Locate the origin of the bogus routes by doing an mtrace to an IP 3. Locate the origin of the bogus routes by doing an mtrace to an IP
address in the bogus range. address in the bogus range.
Symptoms of unicast route redistribution are injection of a large num- Symptoms of unicast route redistribution are injection of a large number
ber of unicast routes (25K+) into DVMRP. The problem may be investi- of unicast routes (25K+) into DVMRP. The problem may be investigated via
gated via the following procedure: the following procedure:
1. Examine the routing table. The DVMRP routing table may be examined 1. Examine the routing table. The DVMRP routing table may be examined
remotely via mstat -r, or locally (for mrouted) by sending the USR1 remotely via mstat -r, or locally (for mrouted) by sending the USR1
signal to mrouted, generating the /var/tmp/mrouted.dump file. For signal to mrouted, generating the /var/tmp/mrouted.dump file. For
protocol independent multicast routing protocols (such as Sparse-Mode protocol independent multicast routing protocols (such as Sparse-Mode
PIM), examine the unicast routing table. PIM), examine the unicast routing table.
2. Check if a single site is the predominant route injector. This 2. Check if a single site is the predominant route injector. This site
site is likely to be the problem. One way to check this is to mtrace is likely to be the problem. One way to check this is to mtrace to
to addresses in a number of "suspect" prefixes. addresses in a number of "suspect" prefixes.
3. If your router supports it, set a route limit on the DVMRP tunnel 3. If your router supports it, set a route limit on the DVMRP tunnel
interface. A limit of 7000 routes is currently recommended. You may interface. A limit of 7000 routes is currently recommended. You may also
also wish to set "route-hog notification" at 5000 routes. wish to set "route-hog notification" at 5000 routes.
Non-pruning DVMRP routers are those which maintain groups in the mul- Non-pruning DVMRP routers are those which maintain groups in the
ticast routing table although there are no downstream subscribers. The
problem can be solved via the following procedure: multicast routing table although there are no downstream subscribers.
The problem can be solved via the following procedure:
1. Check the router version number using mstat or mrinfo. Non-pruning 1. Check the router version number using mstat or mrinfo. Non-pruning
routers include mrouted versions prior to 3, Cisco Systems IOS prior routers include mrouted versions prior to 3, Cisco Systems IOS prior to
to version 11.0(3), and Bay Networks implementations prior to 9.0. version 11.0(3), and Bay Networks implementations prior to 9.0.
2. Confirm lack of pruning as follows. First, dump the multicast for- 2. Confirm lack of pruning as follows. First, dump the multicast
warding table. This can be done remotely with mstat -N, or locally forwarding table. This can be done remotely with mstat -N, or locally
(for mrouted) by sending the USR2 signal to mrouted, generating the (for mrouted) by sending the USR2 signal to mrouted, generating the
/var/tmp/mrouted.cache file. /var/tmp/mrouted.cache file.
3. Check the forwarding table to see if an interface is in the outgo- 3. Check the forwarding table to see if an interface is in the outgoing
ing interface list for every entry in the multicast forwarding table. interface list for every entry in the multicast forwarding table. If
If so, it is likely that a non-pruner lies downstream in that direc- so, it is likely that a non-pruner lies downstream in that direction.
tion.
4. You can confirm the existence of a non-pruner by creating a tempo- 4. You can confirm the existence of a non-pruner by creating a
rary, unadvertised, session and sending (preferably with a low data temporary, unadvertised, session and sending (preferably with a low data
rate) data to that group. After a few moments, dump the forwarding rate) data to that group. After a few moments, dump the forwarding
table again. If any interfaces appear in the outgoing interface list table again. If any interfaces appear in the outgoing interface list of
of the entry for your test stream, then non-pruners lie in those the entry for your test stream, then non-pruners lie in those
directions. directions.
5. If a non-pruner exists downstream, use mrtree to follow the path of 5. If a non-pruner exists downstream, use mrtree to follow the path of
the data downstream to the non-pruning router(s). the data downstream to the non-pruning router(s).
6. If your router supports it, enable the reject non-pruners option. 6. If your router supports it, enable the reject non-pruners option. If
If not, and the unpruned interface is a tunnel, consider disabling the not, and the unpruned interface is a tunnel, consider disabling the
tunnel. tunnel.
5. Appendix - Multicast Diagnostic Tools 6. Appendix - Multicast Diagnostic Tools
5.1. Types of tools 6.1. Types of tools
Multicast diagnostic tools typically fall into the following cate- Multicast diagnostic tools typically fall into the following categories:
gories:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
| RTP monitoring tools | RTPmon | | RTP monitoring tools | RTPmon |
| | Msessmon | | | Msessmon |
| | RTPquality | | | RTPquality |
| | RTPdump | | | RTPdump |
| | RTPcast/RTPlisten | | | RTPcast/RTPlisten |
| | Duppkts | | | Duppkts |
| | | | | |
skipping to change at page 10, line 47 skipping to change at page 12, line 4
| | Multicast heartbeat | | | Multicast heartbeat |
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
| Network analysis | tcpdump | | Network analysis | tcpdump |
| tools | Dr. Watson | | tools | Dr. Watson |
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
RTP monitoring tools are used to monitor the transmission quality and RTP monitoring tools are used to monitor the transmission quality and
popularity of individual sessions. Multicast router diagnostics are
used to obtain information on the configuration and state of multicast popularity of individual sessions. Multicast router diagnostics are used
to obtain information on the configuration and state of multicast
routers. MBONE mapping tools are used to map out the topology for a routers. MBONE mapping tools are used to map out the topology for a
particular group. These tools can show the topology at the level of particular group. These tools can show the topology at the level of
individual systems, or at the level of autonomous system connections. individual systems, or at the level of autonomous system connections.
Multicast traceroute tools are used to trace the path between a source Multicast traceroute tools are used to trace the path between a source
and destination. Network Operations Center tools are used to monitor and destination. Network Operations Center tools are used to monitor the
the state of network devices within an autonomous system. Network state of network devices within an autonomous system. Network analysis
analysis tools (such as tcpdump and Dr. Watson) are used to analyze tools (such as tcpdump and Dr. Watson) are used to analyze traffic on
traffic on the network. the network.
5.2. Facilities utilized 6.2. Facilities utilized
Multicast diagnostic tools typically rely on one or more of the fol- Multicast diagnostic tools typically rely on one or more of the
lowing facilities: following facilities:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
| RTCP source and | RTPmon | | RTCP source and | RTPmon |
| receiver reports | Msessmon | | receiver reports | Msessmon |
| | RTPquality | | | RTPquality |
| | RTPdump | | | RTPdump |
| | RTPcast/RTPlisten | | | RTPcast/RTPlisten |
| | Duppkts | | | Duppkts |
| | | | | |
skipping to change at page 11, line 53 skipping to change at page 14, line 4
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
| Internal structures | tcpdump | | Internal structures | tcpdump |
| | netstat | | | netstat |
| | mrouted.dump, mrouted.cache | | | mrouted.dump, mrouted.cache |
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Tools using RTCP reports analyze RTCP source and receiver reports, Tools using RTCP reports analyze RTCP source and receiver reports,
providing information on packet loss, inter-arrival jitter, bandwidth providing information on packet loss, inter-arrival jitter, bandwidth
availability, or listenership. These tools therefore will only work
with RTP implementations which support RTCP reporting. Tools using
SNMP MIBs perform queries for variables in the IGMP, multicast rout-
ing, DVMRP, and PIM MIBs. As a result, these tools depend on implemen-
tation of the relevant SNMP MIBs in the network devices that are being
monitored. Tools based IGMP ASK_NEIGHBORS messages use these messages
to map portions of the MBONE, and thus will only work with routers
implementing DVMRP. Tools based on IGMP tracing perform a multicast
traceroute. These tools are typically only useful in cases where mul-
ticast routers along the path have a route back to the source.
Diagnostic tools may use more than one of these facilities. For exam- availability, or listenership. These tools therefore will only work with
ple, mstat makes use of SNMP MIBs, as well as the IGMP ASK_NEIGHBORS RTP implementations which support RTCP reporting. Tools using SNMP MIBs
perform queries for variables in the IGMP, multicast routing, DVMRP, and
PIM MIBs. As a result, these tools depend on implementation of the
relevant SNMP MIBs in the network devices that are being monitored.
Tools based IGMP ASK_NEIGHBORS messages use these messages to map
portions of the MBONE, and thus will only work with routers implementing
DVMRP. Tools based on IGMP tracing perform a multicast traceroute. These
tools are typically only useful in cases where multicast routers along
the path have a route back to the source.
Diagnostic tools may use more than one of these facilities. For example,
mstat makes use of SNMP MIBs, as well as the IGMP ASK_NEIGHBORS
facility. facility.
5.3. RTP monitoring tools 6.3. RTP monitoring tools
This class of tools provides information required to monitor the per- This class of tools provides information required to monitor the
formance of RTP-based applications. performance of RTP-based applications.
5.3.1. RTPmon 6.3.1. RTPmon
Authors Authors
David Bacher, Andrew Swan, and Lawrence A. Rowe David Bacher, Andrew Swan, and Lawrence A. Rowe
{drbacher,aswan,rowe}@cs.berkeley.edu {drbacher,aswan,rowe}@cs.berkeley.edu
Computer Science Division - EECS Computer Science Division - EECS
University of California University of California
Berkeley, CA 94720-1776 Berkeley, CA 94720-1776
Description Description
RTPmon allows network administrators or support personnel to moni- RTPmon allows network administrators or support personnel to monitor
tor listenership as well as session quality experienced by sub- listenership as well as session quality experienced by subscribers.
scribers. The tool also facilitates tracing the cause of problems The tool also facilitates tracing the cause of problems resulting in
resulting in quality degradation. To accomplish this task, RTPmon quality degradation. To accomplish this task, RTPmon summarizes and
summarizes and analyzes information provided by RTCP source and analyzes information provided by RTCP source and receiver reports.
receiver reports.
Receivers are displayed for a given sender in the form of a spread- Receivers are displayed for a given sender in the form of a
sheet, with cells being filled in with metrics such as packet loss spreadsheet, with cells being filled in with metrics such as packet
rate or jitter. Clicking on a cell displays a stripchart of statis- loss rate or jitter. Clicking on a cell displays a stripchart of
tics on packet loss rate, smoothed packet loss rate and jitter. statistics on packet loss rate, smoothed packet loss rate and jitter.
From the stripchart it is possible to launch an mtrace between the From the stripchart it is possible to launch an mtrace between the
sender and the receiver, a convenient way of diagnosing network sender and the receiver, a convenient way of diagnosing network
problems along the multicast distribution path. Clicking on a problems along the multicast distribution path. Clicking on a
receiver or sender displays summary information. receiver or sender displays summary information.
For groups with large memberships, the display may be limited to For groups with large memberships, the display may be limited to
members surpassing a given threshold in packet loss rate or jitter. members surpassing a given threshold in packet loss rate or jitter.
Using RTPmon it is possible to sort receivers for a given sender Using RTPmon it is possible to sort receivers for a given sender
according to maximum or average loss. according to maximum or average loss.
skipping to change at page 13, line 20 skipping to change at page 15, line 28
IGMP multicast trace (if installed) IGMP multicast trace (if installed)
Availability Availability
RTPmon is available for UNIX and may be obtained from: RTPmon is available for UNIX and may be obtained from:
ftp://mm-ftp.cs.berkeley.edu/pub/rtpmon/ ftp://mm-ftp.cs.berkeley.edu/pub/rtpmon/
Bug reports and suggestions should be sent to: Bug reports and suggestions should be sent to:
rtpmon@bmrc.berkeley.edu. rtpmon@bmrc.berkeley.edu.
5.3.2. RTPcast/RTPlisten, RTPquality, Duppkts, RTPdump, RTPtools, 6.3.2. RTPcast/RTPlisten, RTPquality, Duppkts, RTPdump, RTPtools,
Msessmon, Mpoll Msessmon, Mpoll
Author Author
Mpoll: Andrew Patrick <andrew@calvin.dgbt.doc.ca> Mpoll: Andrew Patrick <andrew@calvin.dgbt.doc.ca>
Description Description
RTPcast listens to RTCP receiver reports and forwards data to RTPcast listens to RTCP receiver reports and forwards data to another
another multicast group; RTPlisten then listens to that group. RTP- multicast group; RTPlisten then listens to that group. RTPdump
dump listens for, and dumps RTP and RTCP packets. Duppkts listens listens for, and dumps RTP and RTCP packets. Duppkts listens on a
on a multicast group and port, and reports the number of packets multicast group and port, and reports the number of packets received
received and lost, as well as the number of duplicates. RTPquality and lost, as well as the number of duplicates. RTPquality listens to
listens to RTCP receiver reports and writes data on packet loss, as RTCP receiver reports and writes data on packet loss, as well as late
well as late and non-sequenced packets. RTPtools allows recording and non-sequenced packets. RTPtools allows recording and playback of
and playback of RTP sessions. Msessmon provides a routemap of par- RTP sessions. Msessmon provides a routemap of participants in RTP
ticipants in RTP conferences as well as stripcharts of statistics conferences as well as stripcharts of statistics on RTP packet loss
on RTP packet loss and jitter. Mpoll is a survey collection tool and jitter. Mpoll is a survey collection tool that can be used to
that can be used to collect quality ratings during multicast ses- collect quality ratings during multicast sessions.
sions.
Example Example
Information on these tools is available from: Information on these tools is available from:
http://sauce.mmlab.uninett.no/mice-nsc/tools.html http://sauce.mmlab.uninett.no/mice-nsc/tools.html
Facilities used Facilities used
RTCP source and receiver reports RTCP source and receiver reports
Availability Availability
Binaries for RTPcast/RTPlisten are available from: Binaries for RTPcast/RTPlisten are available from:
ftp://sauce.uio.no/mice-nsc/util/rtp ftp://sauce.uio.no/mice-nsc/util/rtp
skipping to change at page 14, line 16 skipping to change at page 16, line 31
Source code for RTPtools is available at: Source code for RTPtools is available at:
ftp://sauce.uio.no/mice-nsc/util/rtptools/rtptools-1.9.tar.gz ftp://sauce.uio.no/mice-nsc/util/rtptools/rtptools-1.9.tar.gz
Source and binaries for Msessmon is available at: Source and binaries for Msessmon is available at:
ftp://sauce.uio.no/mice-nsc/util/msessmon/ ftp://sauce.uio.no/mice-nsc/util/msessmon/
Source and binaries for Mpoll is available at: Source and binaries for Mpoll is available at:
ftp://sauce.uio.no/mice-nsc/util/mpoll/ ftp://sauce.uio.no/mice-nsc/util/mpoll/
5.4. Multicast router diagnostics 6.4. Multicast router diagnostics
This class of tools facilitates monitoring and management of multicast This class of tools facilitates monitoring and management of multicast
routers. routers.
5.4.1. mrouted.dump, mrouted.cache 6.4.1. mrouted.dump, mrouted.cache
Author Author
Bill Fenner, fenner@parc.xerox.com Bill Fenner, fenner@research.att.com
Description Description
Sending the USR1 signal to mrouted dumps the internal routing table Sending the USR1 signal to mrouted dumps the internal routing table
to /var/tmp/mrouted.dump; sending the USR2 signal dumps the for- to /var/tmp/mrouted.dump; sending the USR2 signal dumps the
warding cache to /var/tmp/mrouted.cache. forwarding cache to /var/tmp/mrouted.cache.
Further information on mrouted and the mrouted.dump and Further information on mrouted and the mrouted.dump and mrouted.cache
mrouted.cache file formats is available in the mrouted man page. file formats is available in the mrouted man page.
Example Example
% cat mrouted.dump % cat mrouted.dump
vifs_with_neighbors = 2 vifs_with_neighbors = 2
Virtual Interface Table Virtual Interface Table
Vif Name Local-Address M Thr Rate Flags Vif Name Local-Address M Thr Rate
0 ed0 128.31.107.1 subnet: 128.31.107/24 1 1 0 querier Flags
0 ed0 128.31.107.1 subnet: 128.31.107/24 1 1 0
querier
peers: 128.31.107.249 (3.8) (0xe) peers: 128.31.107.249 (3.8) (0xe)
groups: 239.109.100.200 groups: 239.109.100.200
224.0.0.2 224.0.0.2
224.0.0.4 224.0.0.4
pkts in : 4075 pkts in : 4075
pkts out: 0 pkts out: 0
1 ed0 128.31.107.1 tunnel: 204.67.107.11 1 32 500 1 ed0 128.31.107.1 tunnel: 204.67.107.11 1 32 500
peers: 204.67.107.11 (11.2) (0x1a) peers: 204.67.107.11 (11.2) (0x1a)
pkts in : 0 pkts in : 0
skipping to change at page 15, line 42 skipping to change at page 18, line 14
Facilities used Facilities used
Internal facilities (forwarding cache and routing table) Internal facilities (forwarding cache and routing table)
Availability Availability
The SNMP-capable mrouted distribution is available at: The SNMP-capable mrouted distribution is available at:
ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/ ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/
5.4.2. mrinfo 6.4.2. mrinfo
Author Author
Van Jacobson, van@ee.lbl.gov Van Jacobson, van@ee.lbl.gov
Description Description
mrinfo displays information about a multicast router; to do this, mrinfo displays information about a multicast router; to do this, it
it uses the IGMP ASK_NEIGHBORS message to discover the router's uses the IGMP ASK_NEIGHBORS message to discover the router's physical
physical and virtual interfaces. Routers are also queried for their and virtual interfaces. Routers are also queried for their version
version number, and if this query is successful, for their metrics, number, and if this query is successful, for their metrics,
thresholds, and flags. Results are printed in an indented list for- thresholds, and flags. Results are printed in an indented list format
mat similar to that for map-mbone. similar to that for map-mbone.
Example Example
% mrinfo 192.80.214.199 % mrinfo 192.80.214.199
192.80.214.199 (collegepk-mbone1.bbnplanet.net) [version 11.2,prune,mtrace,snmp]: 192.80.214.199 (collegepk-mbone1.bbnplanet.net) [version
11.2,prune,mtrace,snmp]:
128.167.252.196 -> 0.0.0.0 (local) [1/0/pim/querier/leaf] 128.167.252.196 -> 0.0.0.0 (local) [1/0/pim/querier/leaf]
192.80.214.199 -> 0.0.0.0 (local) [1/0/pim/querier/leaf] 192.80.214.199 -> 0.0.0.0 (local) [1/0/pim/querier/leaf]
192.41.177.196 -> 0.0.0.0 (local) [1/0/pim/querier/down/leaf] 192.41.177.196 -> 0.0.0.0 (local) [1/0/pim/querier/down/leaf]
128.167.252.196 -> 128.167.254.165 (devo.sura.net) [1/32/tunnel/querier/down/leaf] 128.167.252.196 -> 128.167.254.165 (devo.sura.net)
[1/32/tunnel/querier/down/leaf]
128.167.252.196 -> 131.119.0.197 (paloalto-mbone1.bbnplanet.net) 128.167.252.196 -> 131.119.0.197 (paloalto-mbone1.bbnplanet.net)
[1/64/tunnel/pim/querier] [1/64/tunnel/pim/querier]
128.167.252.196 -> 199.94.207.2 (cambridge1-mbone1.bbnplanet.net) 128.167.252.196 -> 199.94.207.2 (cambridge1-mbone1.bbnplanet.net)
[1/32/tunnel/pim/querier] [1/32/tunnel/pim/querier]
128.167.252.196 -> 137.39.43.34 (MBONE1.UU.NET) [1/32/tunnel/querier] 128.167.252.196 -> 137.39.43.34 (MBONE1.UU.NET) [1/32/tunnel/querier]
128.167.252.196 -> 192.41.177.199 (wtn-ms2.bbnplanet.net) [1/16/tunnel/querier] 128.167.252.196 -> 192.41.177.199 (wtn-ms2.bbnplanet.net)
[1/16/tunnel/querier]
128.167.252.196 -> 128.244.93.3 (sage.jhuapl.edu) [1/32/tunnel/querier] 128.167.252.196 -> 128.244.93.3 (sage.jhuapl.edu) [1/32/tunnel/querier]
128.167.252.196 -> 192.221.34.22 (cdrn.bbnplanet.net) [1/32/tunnel/querier] 128.167.252.196 -> 192.221.34.22 (cdrn.bbnplanet.net)
128.167.252.196 -> 128.167.1.197 (cpk-ms1.ser.bbnplanet.com) [1/16/tunnel/querier] [1/32/tunnel/querier]
128.167.252.196 -> 134.205.93.150 (dilbert.sam.pentagon.mil) [1/32/tunnel/querier] 128.167.252.196 -> 128.167.1.197 (cpk-ms1.ser.bbnplanet.com)
[1/16/tunnel/querier]
128.167.252.196 -> 134.205.93.150 (dilbert.sam.pentagon.mil)
[1/32/tunnel/querier]
128.167.252.196 -> 192.221.48.234 (atlanta3-mbone1.bbnplanet.net) 128.167.252.196 -> 192.221.48.234 (atlanta3-mbone1.bbnplanet.net)
[1/64/tunnel/pim/querier] [1/64/tunnel/pim/querier]
128.167.252.196 -> 204.167.201.38 (dallas2-mbone1.bbnplanet.net) 128.167.252.196 -> 204.167.201.38 (dallas2-mbone1.bbnplanet.net)
[1/64/tunnel/pim/querier] [1/64/tunnel/pim/querier]
128.167.252.196 -> 205.130.85.3 (philipii.nap.edu) [1/32/tunnel/querier/down/leaf] 128.167.252.196 -> 205.130.85.3 (philipii.nap.edu)
128.167.252.196 -> 128.175.13.36 (pfet.nss.udel.edu) [1/32/tunnel/querier/down/leaf] [1/32/tunnel/querier/down/leaf]
128.167.252.196 -> 192.41.177.197 (wtn-ms1.bbnplanet.net) [1/32/tunnel/querier] 128.167.252.196 -> 128.175.13.36 (pfet.nss.udel.edu)
128.167.252.196 -> 204.148.62.28 (mbone-e.ans.net) [1/32/tunnel/querier] [1/32/tunnel/querier/down/leaf]
128.167.252.196 -> 205.128.246.2 (usnrctc.bbnplanet.net) [1/32/tunnel/pim/querier] 128.167.252.196 -> 192.41.177.197 (wtn-ms1.bbnplanet.net)
[1/32/tunnel/querier]
128.167.252.196 -> 204.148.62.28 (mbone-e.ans.net)
[1/32/tunnel/querier]
128.167.252.196 -> 205.128.246.2 (usnrctc.bbnplanet.net)
[1/32/tunnel/pim/querier]
Facilities used Facilities used
IGMP ASK_NEIGHBORS message (DVMRP) IGMP ASK_NEIGHBORS message (DVMRP)
Availability Availability
mrinfo is available for UNIX and is included in the SNMP-capable mrinfo is available for UNIX and is included in the SNMP-capable
mrouted distribution, available at: mrouted distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/ ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/
mrinfo is also available in the MVIEW distribution, available at: mrinfo is also available in the MVIEW distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mview/ ftp://ftp.merit.edu/net-research/mbone/mview/
5.4.3. netstat 6.4.3. netstat
Author Author
Unknown Unknown
Description Description
On multicast-enabled systems, netstat is typically extended so as On multicast-enabled systems, netstat is typically extended so as to
to provide information on virtual interfaces and the multicast for- provide information on virtual interfaces and the multicast
warding cache (-g option), as well as multicast routing statistics forwarding cache (-g option), as well as multicast routing statistics
(-gs option), and igmp behavior (-s option). (-gs option), and igmp behavior (-s option).
Example Example
%netstat -g %netstat -g
Virtual Interface Table Virtual Interface Table
Vif Thresh Rate Local-Address Remote-Address Pkts-In Pkts-Out Vif Thresh Rate Local-Address Remote-Address Pkts-In
0 1 0 128.15.2.120 16323 385 Pkts-Out
1 32 512 128.15.2.120 202.34.126.2 2 0 0 1 0 128.15.2.120 16323
385
1 32 512 128.15.2.120 202.34.126.2 2
0
Multicast Forwarding Cache Multicast Forwarding Cache
Origin Group Packets In-Vif Out-Vifs:Ttls Origin Group Packets In-Vif Out-Vifs:Ttls
128.15.2.120 224.2.195.166 281 0 128.15.2.120 224.2.195.166 281 0
128.15.1.110 239.100.101.223 1660 0 128.15.1.110 239.100.101.223 1660 0
128.15.1.135 238.27.27.1 1660 0 128.15.1.135 238.27.27.1 1660 0
128.15.1.110 239.111.111.235 1660 0 128.15.1.110 239.111.111.235 1660 0
... ...
%netstat -gs %netstat -gs
skipping to change at page 18, line 19 skipping to change at page 21, line 8
... ...
Facilities used Facilities used
Netstat accesses system internal data structures in order to carry Netstat accesses system internal data structures in order to carry
out its function. out its function.
Availability Availability
netstat is included with a variety of operating systems, including netstat is included with a variety of operating systems, including
UNIX, OS/2, and Windows. For further information, please consult UNIX, OS/2, and Windows. For further information, please consult the
the netstat man page or documentation. netstat man page or documentation.
5.4.4. mstat 6.4.4. mstat
Author Author
Dave Thaler, dthaler@microsoft.com Dave Thaler, dthaler@microsoft.com
Description Description
mstat is a general purpose tool for obtaining router configuration mstat is a general purpose tool for obtaining router configuration
and status information. In order to perform its task, mstat uti- and status information. In order to perform its task, mstat utilizes
lizes SNMP MIBs (such as the IGMP, multicast routing, PIM, and SNMP MIBs (such as the IGMP, multicast routing, PIM, and DVMRP MIBs),
DVMRP MIBs), as well as ASK_NEIGHBORS IGMP messages. mstat displays as well as ASK_NEIGHBORS IGMP messages. mstat displays the contents
the contents of various MBONE-related data structures in various of various MBONE-related data structures in various formats,
formats, depending on the options selected. Options include: depending on the options selected. Options include:
-G Show the PIM group table -G Show the PIM group table
-I Show the PIM interface table. -I Show the PIM interface table.
-K Show the cached IP multicast route table; works for -K Show the cached IP multicast route table; works for
all SNMP-capable routers. all SNMP-capable routers.
-N Show the IP Multicast Next Hop Table. -N Show the IP Multicast Next Hop Table.
-P Show the PIM neighbor table. -P Show the PIM neighbor table.
-a Show the alternate subnet table. -a Show the alternate subnet table.
-b Show the scoped boundary table. -b Show the scoped boundary table.
-d Show the DVMRP neighbor table. -d Show the DVMRP neighbor table.
skipping to change at page 19, line 9 skipping to change at page 21, line 49
-r Show the DVMRP routing table; similar to a portion of -r Show the DVMRP routing table; similar to a portion of
the mrouted.dump file. the mrouted.dump file.
-t Show the DVMRP routing next hop table; similar to -t Show the DVMRP routing next hop table; similar to
another portion of the mrouted.dump file. another portion of the mrouted.dump file.
-v Show statistics corresponding to the DVMRP interface table. -v Show statistics corresponding to the DVMRP interface table.
Examples Examples
% mstat % mstat
IP Multicast Route Table for bigco.com IP Multicast Route Table for bigco.com
Mcast-group Origin-Subnet InIf UpTime Tmr Pkts Bytes RpF Proto Mcast-group Origin-Subnet InIf UpTime Tmr Pkts Bytes RpF
NTP.MCAST.NET 0.0.0.0/32 0 245341 179 0 0 0 pim Proto
NTP.MCAST.NET 128.232.0.49/32 7 206403 418 3056 293376 17 dvmrp NTP.MCAST.NET 0.0.0.0/32 0 245341 179 0 0 0
NTP.MCAST.NET 128.232.2.209/32 7 206403 417 3027 290592 19 dvmrp pim
NTP.MCAST.NET 143.107.103.5/32 7 592 218 3 228 3 dvmrp NTP.MCAST.NET 128.232.0.49/32 7 206403 418 3056 293376 17
NTP.MCAST.NET 157.161.114.2/32 7 27703 517 411 31236 11 dvmrp dvmrp
IETF-2-VIDEO.MC 0.0.0.0/32 0 245349 175 0 0 0 pim NTP.MCAST.NET 128.232.2.209/32 7 206403 417 3027 290592 19
IETF-2-VIDEO.MC 206.152.163.21/32 7 242567 244 46887 4149336 3388 dvmrp dvmrp
MTRACE.MCAST.NE 0.0.0.0/32 0 1690 177 0 0 0 pim NTP.MCAST.NET 143.107.103.5/32 7 592 218 3 228 3
MTRACE.MCAST.NE 194.104.0.25/32 7 405 483 2 792 0 dvmrp dvmrp
MTRACE.MCAST.NE 206.54.224.150/32 7 456 569 4 1072 4 dvmrp NTP.MCAST.NET 157.161.114.2/32 7 27703 517 411 31236 11
CISCO-RP-DISCOV 0.0.0.0/32 0 245534 0 0 0 0 pim dvmrp
224.0.14.1 203.15.123.99/32 4 17 161 0 0 0 dvmrp IETF-2-VIDEO.MC 0.0.0.0/32 0 245349 175 0 0 0
224.0.92.3 171.68.201.39/32 4 174 4 0 0 0 dvmrp pim
224.2.0.1 13.2.116.11/32 4 150 26 0 0 0 dvmrp IETF-2-VIDEO.MC 206.152.163.21/32 7 242567 244 46887 4149336 3388
224.2.0.1 128.32.38.218/32 4 147 30 0 0 0 dvmrp dvmrp
224.2.2.1 205.226.8.183/32 4 146 30 0 0 0 dvmrp MTRACE.MCAST.NE 0.0.0.0/32 0 1690 177 0 0 0
224.2.20.165 13.2.116.11/32 4 55 119 0 0 0 dvmrp pim
224.2.100.100 13.2.116.11/32 4 87 91 0 0 0 dvmrp MTRACE.MCAST.NE 194.104.0.25/32 7 405 483 2 792 0
SAP.MCAST.NET 164.67.63.7/32 4 114 64 1 855 0 dvmrp dvmrp
SAP.MCAST.NET 193.61.212.130/32 4 153 23 1 868 0 dvmrp MTRACE.MCAST.NE 206.54.224.150/32 7 456 569 4 1072 4
SAP.MCAST.NET 199.94.220.184/32 4 26 152 1 416 0 dvmrp dvmrp
SAP.MCAST.NET 206.154.213.242/32 4 156 19 1 360 0 dvmrp CISCO-RP-DISCOV 0.0.0.0/32 0 245534 0 0 0 0
pim
224.0.14.1 203.15.123.99/32 4 17 161 0 0 0
dvmrp
224.0.92.3 171.68.201.39/32 4 174 4 0 0 0
dvmrp
224.2.0.1 13.2.116.11/32 4 150 26 0 0 0
dvmrp
224.2.0.1 128.32.38.218/32 4 147 30 0 0 0
dvmrp
224.2.2.1 205.226.8.183/32 4 146 30 0 0 0
dvmrp
224.2.20.165 13.2.116.11/32 4 55 119 0 0 0
dvmrp
224.2.100.100 13.2.116.11/32 4 87 91 0 0 0
dvmrp
SAP.MCAST.NET 164.67.63.7/32 4 114 64 1 855 0
dvmrp
SAP.MCAST.NET 193.61.212.130/32 4 153 23 1 868 0
dvmrp
SAP.MCAST.NET 199.94.220.184/32 4 26 152 1 416 0
dvmrp
SAP.MCAST.NET 206.154.213.242/32 4 156 19 1 360 0
dvmrp
... ...
Examples of the many other options are provided in the mstat man pages. Examples of the many other options are provided in the mstat man pages.
Facilities used Facilities used
PIM, DVMRP, IGMP, and multicast routing MIBs PIM, DVMRP, IGMP, and multicast routing MIBs
IGMP ASK_NEIGHBORS message (DVMRP) IGMP ASK_NEIGHBORS message (DVMRP)
Availability Availability
mstat is included in the SNMP-capable mrouted distribution, mstat is included in the SNMP-capable mrouted distribution,
available at: available at:
ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/ ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/
mstat is also available in the MVIEW distribution, available at: mstat is also available in the MVIEW distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mview/ ftp://ftp.merit.edu/net-research/mbone/mview/
5.4.5. mconfig 6.4.5. mconfig
Author Author
Dave Thaler, dthaler@microsoft.com Dave Thaler, dthaler@microsoft.com
Description Description
mconfig allows the user to display and (if the community string is mconfig allows the user to display and (if the community string is
known) to modify the configuration of a multicast router implement- known) to modify the configuration of a multicast router implementing
ing the DVMRP MIB. the DVMRP MIB.
Example Example
For more information on mconfig, please see the man page. For more information on mconfig, please see the man page.
Facilities used Facilities used
DVMRP MIB DVMRP MIB
Availability Availability
mconfig is available for UNIX and is included in the SNMP-capable mconfig is available for UNIX and is included in the SNMP-capable
mrouted distribution, available at: ftp://ftp.merit.edu/net- mrouted distribution, available at: ftp://ftp.merit.edu/net-
research/mbone/mirrors/mrouted/ research/mbone/mirrors/mrouted/
5.5. Multicast traceroute 6.5. Multicast traceroute
5.5.1. mtrace 6.5.1. mtrace
Author Author
Bill Fenner, fenner@parc.xerox.com Bill Fenner, fenner@research.att.com
Description Description
mtrace provides a facility by which to trace the path between a mtrace provides a facility by which to trace the path between a
sender and a receiver of a particular group. This is particularly sender and a receiver of a particular group. This is particularly
useful when used alongside a facility such as RTPmon, which allows useful when used alongside a facility such as RTPmon, which allows
you to identify problem source-receiver pairs. you to identify problem source-receiver pairs.
Note that the utility of mtrace is often limited by the multicast Note that the utility of mtrace is often limited by the multicast
topology. Where multicast and unicast topologies are not aligned topology. Where multicast and unicast topologies are not aligned (as
(as is the case in many multicast-enabled networks) mtrace may not is the case in many multicast-enabled networks) mtrace may not
function. function.
For information on the details of the protocol, see reference [8]. For information on the details of the protocol, see reference [8].
Example Example
% mtrace 131.243.73.36 128.15.1.250 224.2.195.166 % mtrace 131.243.73.36 128.15.1.250 224.2.195.166
Mtrace from 131.243.73.36 to 128.15.1.250 via group 224.2.195.166 Mtrace from 131.243.73.36 to 128.15.1.250 via group 224.2.195.166
Querying full reverse path... * switching to hop-by-hop: Querying full reverse path... * switching to hop-by-hop:
0 bigman.bigco.com (128.15.1.250) 0 bigman.bigco.com (128.15.1.250)
-1 * * littleman.bigco.com (128.15.1.249) DVMRP thresh^ 1 -1 * * littleman.bigco.com (128.15.1.249) DVMRP thresh^ 1
-2 * * * seamr1-gw.nwnet.net (192.35.180.201) DVMRP thresh^ 32 -2 * * * seamr1-gw.nwnet.net (192.35.180.201) DVMRP thresh^ 32
-3 * * seamr2-gw.nwnet.net (192.220.238.130) DVMRP thresh^ 0 -3 * * seamr2-gw.nwnet.net (192.220.238.130) DVMRP thresh^ 0
-4 * * mcast.cac.washington.edu (140.142.116.1) DVMRP thresh^ 32 -4 * * mcast.cac.washington.edu (140.142.116.1) DVMRP thresh^ 32
-5 * * * * dec3800-1-fddi-0.Sacramento.mci.net (204.70.164.29) didn't respond -5 * * * * dec3800-1-fddi-0.Sacramento.mci.net (204.70.164.29) didn't
respond
-6 * * * -6 * * *
-7 * * -7 * *
Resuming... Resuming...
-5 dec3800-1-fddi-0.Sacramento.mci.net (204.70.164.29) DVMRP thresh^ 64 -5 dec3800-1-fddi-0.Sacramento.mci.net (204.70.164.29) DVMRP thresh^
-6 dec3800-2-fddi-0.SanFrancisco.mci.net (204.70.158.61) DVMRP thresh^ 1 64
-6 dec3800-2-fddi-0.SanFrancisco.mci.net (204.70.158.61) DVMRP
thresh^ 1
-7 mbone.nsi.nasa.gov (192.203.230.241) DVMRP thresh^ 64 -7 mbone.nsi.nasa.gov (192.203.230.241) DVMRP thresh^ 64
-8 * * llnl-mr2.es.net (134.55.12.229) DVMRP thresh^ 64 -8 * * llnl-mr2.es.net (134.55.12.229) DVMRP thresh^ 64
-9 * * lbl-mr1.es.net (134.55.12.101) DVMRP thresh^ 8 -9 * * lbl-mr1.es.net (134.55.12.101) DVMRP thresh^ 8
-10 * * mr1.lbl.gov (131.243.64.184) DVMRP thresh^ 32 -10 * * mr1.lbl.gov (131.243.64.184) DVMRP thresh^ 32
-11 * * ir40gw.lbl.gov (131.243.64.1) DVMRP thresh^ 0 -11 * * ir40gw.lbl.gov (131.243.64.1) DVMRP thresh^ 0
-12 * * irals.lbl.gov (131.243.128.6) PIM thresh^ 0 -12 * * irals.lbl.gov (131.243.128.6) PIM thresh^ 0
-13 bl7-36.als.lbl.gov (131.243.73.36) -13 bl7-36.als.lbl.gov (131.243.73.36)
Round trip time 74 ms; total ttl of 72 required. Round trip time 74 ms; total ttl of 72 required.
Waiting to accumulate statistics... Results after 10 seconds: Waiting to accumulate statistics... Results after 10 seconds:
Source Response Dest Overall Packet Statistics For Traffic From Source Response Dest Overall Packet Statistics For
131.243.73.36 128.15.1.250 Packet 131.243.73.36 To 224.2.195.166 Traffic From
131.243.73.36 128.15.1.250 Packet 131.243.73.36 To
224.2.195.166
v __/ rtt 77 ms Rate Lost/Sent = Pct Rate v __/ rtt 77 ms Rate Lost/Sent = Pct Rate
131.243.73.1 131.243.73.1
131.243.128.6 irals.lbl.gov 131.243.128.6 irals.lbl.gov
v ^ ttl 1 6 pps 0/60 = 0% 6 pps v ^ ttl 1 6 pps 0/60 = 0% 6 pps
131.243.128.40 131.243.128.40
131.243.64.1 ir40gw.lbl.gov 131.243.64.1 ir40gw.lbl.gov
v ^ ttl 2 13 pps 0/60 = 0% 6 pps v ^ ttl 2 13 pps 0/60 = 0% 6 pps
131.243.64.184 mr1.lbl.gov 131.243.64.184 mr1.lbl.gov
v ^ ttl 35 9 pps 0/60 = 0% 6 pps v ^ ttl 35 9 pps 0/60 = 0% 6 pps
198.128.16.13 198.128.16.13
skipping to change at page 22, line 4 skipping to change at page 25, line 10
192.35.180.201 seamr1-gw.nwnet.net 192.35.180.201 seamr1-gw.nwnet.net
v ^ ttl 72 0 pps 0/59 = 0% 0 pps v ^ ttl 72 0 pps 0/59 = 0% 0 pps
128.15.1.249 littleman.bigco.com 128.15.1.249 littleman.bigco.com
v __ ttl 72 0 pps ?/59 0 pps v __ ttl 72 0 pps ?/59 0 pps
128.15.1.250 128.15.1.250 128.15.1.250 128.15.1.250
Receiver Query Source Receiver Query Source
Facilities used Facilities used
IGMP multicast trace facility IGMP multicast trace facility
Availability Availability
mtrace is now distributed independently of mrouted. mtrace is now distributed independently of mrouted.
Source code is available from: Source code is available from:
ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1.tar.Z ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1.tar.Z
Binaries: Binaries:
ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-sparc-sunos41x.tar.Z ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-sparc-sunos41x.tar.Z
ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-sparc-solaris2.tar.Z ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-sparc-solaris2.tar.Z
ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-alpha-osf1.tar.Z ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-alpha-osf1.tar.Z
ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-sgi-irix.tar.Z ftp://ftp.parc.xerox.com/pub/net-research/ipmulti/mtrace5.1-sgi-irix.tar.Z
5.6. MBONE mapping tools 6.6. MBONE mapping tools
5.6.1. mrtree 6.6.1. mrtree
Author Author
Dave Thaler, dthaler@microsoft.com Dave Thaler, dthaler@microsoft.com
Andy Adams, ala@merit.edu Andy Adams, ala@merit.edu
Description Description
mrtree uses a combination of IGMP and SNMP queries to discover the mrtree uses a combination of IGMP and SNMP queries to discover the
actual and potential multicast (sub)trees for a given source and actual and potential multicast (sub)trees for a given source and
group, rooted at a given router. An actual tree, discovered using group, rooted at a given router. An actual tree, discovered using the
the multicast routing MIB, consists of routers which are currently multicast routing MIB, consists of routers which are currently
forwarding multicast traffic to a group from a given source. A forwarding multicast traffic to a group from a given source. A
potential tree, discovered using the DVMRP MIB, is one which would potential tree, discovered using the DVMRP MIB, is one which would
exist if every host were a member of the group. exist if every host were a member of the group.
Example Example
% mrtree mbone.merit.edu 224.2.143.24 204.62.246.73 % mrtree mbone.merit.edu 224.2.143.24 204.62.246.73
Actual distribution tree rooted at mbone.merit.edu for group 224.2.143.24 Actual distribution tree rooted at mbone.merit.edu for group 224.2.143.24
and source 204.62.246.73... and source 204.62.246.73...
0 mbone.merit.edu (198.108.2.20) [ver 3.8,prune,genid,mtrace], 0 mbone.merit.edu (198.108.2.20) [ver 3.8,prune,genid,mtrace],
247390 pkts 247390 pkts
1 cujo.merit.edu (198.108.60.97) [ver 3.6,prune,genid,mtrace], 333448 1 cujo.merit.edu (198.108.60.97) [ver 3.6,prune,genid,mtrace], 333448
6 pkts (1347%) 6 pkts (1347%)
2 subnet: 198.108.60/24 2 subnet: 198.108.60/24
2 shockwave.merit.edu (198.108.60.69) [ver 3.8,prune,genid,mtrace,snmp], 2 shockwave.merit.edu (198.108.60.69) [ver
3.8,prune,genid,mtrace,snmp],
1239130 pkts (500%) 1239130 pkts (500%)
1 tibia.cic.net (192.217.65.100) [ver 3.8,prune,genid,mtrace] 1 tibia.cic.net (192.217.65.100) [ver 3.8,prune,genid,mtrace]
... (No response from tibia.cic.net) ... (No response from tibia.cic.net)
2 fibula.cic.net (192.217.65.101) [ver 3.8,prune,genid,mtrace] ? 2 fibula.cic.net (192.217.65.101) [ver 3.8,prune,genid,mtrace] ?
2 dcl2.gw.uiuc.edu (192.17.2.8) [ver 1.0] ? 2 dcl2.gw.uiuc.edu (192.17.2.8) [ver 1.0] ?
2 goober.mci.net (204.70.104.45) [ver 3.6,prune,genid,mtrace] ? 2 goober.mci.net (204.70.104.45) [ver 3.6,prune,genid,mtrace] ?
... (goober.mci.net did not respond to DVMRP 'NEIGHBORS' msg) ... (goober.mci.net did not respond to DVMRP 'NEIGHBORS' msg)
1 a-wing.jvnc.net (130.94.40.6) [ver 3.3] 1 a-wing.jvnc.net (130.94.40.6) [ver 3.3]
... (a-wing.jvnc.net does not support SNMP) ... (a-wing.jvnc.net does not support SNMP)
2 liberty-eth0/0.jvnc.net (130.94.40.1) [ver 10.2] ? 2 liberty-eth0/0.jvnc.net (130.94.40.1) [ver 10.2] ?
2 noc.hpc.org (192.187.8.2) [ver 3.8,prune,genid,mtrace] ? 2 noc.hpc.org (192.187.8.2) [ver 3.8,prune,genid,mtrace] ?
2 liberty.jvnc.net (130.94.40.201) [ver 10.2] ? 2 liberty.jvnc.net (130.94.40.201) [ver 10.2] ?
2 dstest.ds.internic.net (198.49.45.4) [ver 3.8,prune,genid,mtrace] ? 2 dstest.ds.internic.net (198.49.45.4) [ver 3.8,prune,genid,mtrace]
?
2 cybercast.cc.nus.sg (137.132.9.70) [ver 3.6,prune,genid,mtrace] ? 2 cybercast.cc.nus.sg (137.132.9.70) [ver 3.6,prune,genid,mtrace] ?
... (cybercast.cc.nus.sg did not respond to DVMRP 'NEIGHBORS' msg) ... (cybercast.cc.nus.sg did not respond to DVMRP 'NEIGHBORS'
msg)
Facilities used Facilities used
DVMRP and multicast routing MIBs DVMRP and multicast routing MIBs
IGMP ASK_NEIGHBORS message (DVMRP) IGMP ASK_NEIGHBORS message (DVMRP)
Availability Availability
mrtree is available for UNIX and is included in the mrtree is available for UNIX and is included in the
SNMP-capable mrouted distribution, available at: SNMP-capable mrouted distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/ ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/
mrtree is also available in the MVIEW distribution, available at: mrtree is also available in the MVIEW distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mview/ ftp://ftp.merit.edu/net-research/mbone/mview/
5.6.2. map-mbone 6.6.2. map-mbone
Author Author
Pavel Curtis, pavel@parc.xerox.com Pavel Curtis, pavel@parc.xerox.com
Description Description
map-mbone is useful for discovering the topology within a DVMRP map-mbone is useful for discovering the topology within a DVMRP
routing domain; to do this, it uses the IGMP ASK_NEIGHBORS message routing domain; to do this, it uses the IGMP ASK_NEIGHBORS message to
to discover the neighbors of the starting router. If the -f discover the neighbors of the starting router. If the -f (flooding)
(flooding) option is enabled (this is the default if no starting option is enabled (this is the default if no starting router is
router is specified), then once these neighbors are discovered, specified), then once these neighbors are discovered, they too are
they too are queried. This continues until the leaf routers are queried. This continues until the leaf routers are reached. This
reached. This option should be used with care since it can result option should be used with care since it can result in excessive load
in excessive load on multicast routers. on multicast routers.
If a starting router is specified but the -f option is not used, If a starting router is specified but the -f option is not used, then
then the search terminates after the first hop routers are discov- the search terminates after the first hop routers are discovered, the
ered, the output of map-mbone is very similar to that for mrinfo. output of map-mbone is very similar to that for mrinfo. Routers
Routers discovered by map-mbone are queried for their version num- discovered by map-mbone are queried for their version numbers, and if
bers, and if this query is successful, for their metrics, thresh- this query is successful, for their metrics, thresholds, and flags,
olds, and flags, and the results are presented in an indented list and the results are presented in an indented list format.
format.
Example Example
% map-mbone 192.80.214.199 % map-mbone 192.80.214.199
192.41.177.196: alias for 128.167.252.196 192.41.177.196: alias for 128.167.252.196
128.167.252.196 (collegepk-mbone1.bbnplanet.net): <v11.2> 128.167.252.196 (collegepk-mbone1.bbnplanet.net): <v11.2>
192.41.177.196: 192.41.177.196 [1/0/querier/down] 192.41.177.196: 192.41.177.196 [1/0/querier/down]
192.80.214.199: 192.80.214.199 (collegepk-mbone1.bbnplanet.net) [1/0/querier] 192.80.214.199: 192.80.214.199 (collegepk-mbone1.bbnplanet.net)
128.167.252.196: 205.128.246.2 (usnrctc.bbnplanet.net) [1/32/tunnel/querier] [1/0/querier]
204.148.62.28 (mbone-e.ans.net) [1/32/tunnel/querier] 128.167.252.196: 205.128.246.2 (usnrctc.bbnplanet.net)
192.41.177.197 (wtn-ms1.bbnplanet.net) [1/32/tunnel/querier] [1/32/tunnel/querier]
128.175.13.36 (pfet.nss.udel.edu) [1/32/tunnel/querier/down] 204.148.62.28 (mbone-e.ans.net)
205.130.85.3 (philipii.nap.edu) [1/32/tunnel/querier/down] [1/32/tunnel/querier]
204.167.201.38 (dallas2-mbone1.bbnplanet.net) [1/64/tunnel/querier] 192.41.177.197 (wtn-ms1.bbnplanet.net)
192.221.48.234 (atlanta3-mbone1.bbnplanet.net) [1/64/tunnel/querier] [1/32/tunnel/querier]
134.205.93.150 (dilbert.sam.pentagon.mil) [1/32/tunnel/querier] 128.175.13.36 (pfet.nss.udel.edu)
128.167.1.197 (cpk-ms1.ser.bbnplanet.com) [1/16/tunnel/querier] [1/32/tunnel/querier/down]
192.221.34.22 (cdrn.bbnplanet.net) [1/32/tunnel/querier] 205.130.85.3 (philipii.nap.edu)
128.244.93.3 (sage.jhuapl.edu) [1/32/tunnel/querier] [1/32/tunnel/querier/down]
192.41.177.199 (wtn-ms2.bbnplanet.net) [1/16/tunnel/querier] 204.167.201.38 (dallas2-mbone1.bbnplanet.net)
[1/64/tunnel/querier]
192.221.48.234 (atlanta3-mbone1.bbnplanet.net)
[1/64/tunnel/querier]
134.205.93.150 (dilbert.sam.pentagon.mil)
[1/32/tunnel/querier]
128.167.1.197 (cpk-ms1.ser.bbnplanet.com)
[1/16/tunnel/querier]
192.221.34.22 (cdrn.bbnplanet.net)
[1/32/tunnel/querier]
128.244.93.3 (sage.jhuapl.edu)
[1/32/tunnel/querier]
192.41.177.199 (wtn-ms2.bbnplanet.net)
[1/16/tunnel/querier]
137.39.43.34 (MBONE1.UU.NET) [1/32/tunnel/querier] 137.39.43.34 (MBONE1.UU.NET) [1/32/tunnel/querier]
199.94.207.2 (cambridge1-mbone1.bbnplanet.net) [1/32/tunnel/querier] 199.94.207.2 (cambridge1-mbone1.bbnplanet.net)
131.119.0.197 (paloalto-mbone1.bbnplanet.net) [1/64/tunnel/querier] [1/32/tunnel/querier]
128.167.254.165 (devo.sura.net) [1/32/tunnel/querier/down] 131.119.0.197 (paloalto-mbone1.bbnplanet.net)
128.167.252.196 (collegepk-mbone1.bbnplanet.net) [1/0/querier] [1/64/tunnel/querier]
128.167.254.165 (devo.sura.net)
[1/32/tunnel/querier/down]
128.167.252.196 (collegepk-mbone1.bbnplanet.net)
[1/0/querier]
192.80.214.199 (collegepk-mbone1.bbnplanet.net): alias for 128.167.252.196 192.80.214.199 (collegepk-mbone1.bbnplanet.net): alias for
128.167.252.196
Facilities used Facilities used
IGMP ASK_NEIGHBORS message (DVMRP) IGMP ASK_NEIGHBORS message (DVMRP)
Availability Availability
map-mbone is available for UNIX, and the software and manual pages are included map-mbone is available for UNIX, and the software and manual pages are
included
in the SNMP-capable mrouted distribution, available at: in the SNMP-capable mrouted distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/ ftp://ftp.merit.edu/net-research/mbone/mirrors/mrouted/
5.6.3. asn 6.6.3. asn
Author Author
Dave Thaler, dthaler@microsoft.com Dave Thaler, dthaler@microsoft.com
Description Description
asn gives the AS number of a given IP address by querying the rout- asn gives the AS number of a given IP address by querying the routing
ing arbiter database. arbiter database.
Example Example
% asn 141.213.10.41 % asn 141.213.10.41
AS237 AS237
Facilities used Facilities used
Routing arbiter database Routing arbiter database
skipping to change at page 25, line 4 skipping to change at page 28, line 26
Example Example
% asn 141.213.10.41 % asn 141.213.10.41
AS237 AS237
Facilities used Facilities used
Routing arbiter database Routing arbiter database
Availability Availability
asn is included in the MVIEW distribution, available at: asn is included in the MVIEW distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mview/ ftp://ftp.merit.edu/net-research/mbone/mview/
5.6.4. asname 6.6.4. asname
Author Author
Dave Thaler, dthaler@microsoft.com Dave Thaler, dthaler@microsoft.com
Description Description
asname gets the name of an AS, given the AS number by querying the asname gets the name of an AS, given the AS number by querying the
WHOIS database. WHOIS database.
skipping to change at page 25, line 30 skipping to change at page 29, line 4
% asname 237 % asname 237
NSFNETTEST14-AS NSFNETTEST14-AS
Facilities used Facilities used
WHOIS database WHOIS database
Availability Availability
asname is included in the MVIEW distribution, available at: asname is included in the MVIEW distribution, available at:
ftp://ftp.merit.edu/net-research/mbone/mview/ ftp://ftp.merit.edu/net-research/mbone/mview/
5.7. Network Operations Center tools 6.7. Network Operations Center tools
These tools are suitable for use in a Network Operations Center. These tools are suitable for use in a Network Operations Center.
5.7.1. MVIEW 6.7.1. MVIEW
Authors Authors
Dave Thaler, dthaler@microsoft.com Dave Thaler, dthaler@microsoft.com
Andy Adams, ala@merit.edu Andy Adams, ala@merit.edu
Description Description
MVIEW uses utilities such as mstat, mtrace, mrtree, asn and asname MVIEW uses utilities such as mstat, mtrace, mrtree, asn and asname in
in order to produce a graphical depiction of the multicast network order to produce a graphical depiction of the multicast network
topology and the actual and potential multicast trees for a given topology and the actual and potential multicast trees for a given
group and source. group and source.
Example Example
Further information on MVIEW as well as examples are available from: Further information on MVIEW as well as examples are available from:
http://www.merit.edu/net-research/mbone/mviewdoc/Welcome.html http://www.merit.edu/net-research/mbone/mviewdoc/Welcome.html
Facilities used Facilities used
PIM, DVMRP, IGMP, and multicast routing MIBs (mstat) PIM, DVMRP, IGMP, and multicast routing MIBs (mstat)
IGMP ASK_NEIGHBORS message (mrinfo) IGMP ASK_NEIGHBORS message (mrinfo)
Routing arbiter database (asn) Routing arbiter database (asn)
WHOIS database (asname) WHOIS database (asname)
Availability Availability
MVIEW is available for UNIX, and can be obtained from: MVIEW is available for UNIX, and can be obtained from:
skipping to change at page 26, line 19 skipping to change at page 29, line 45
WHOIS database (asname) WHOIS database (asname)
Availability Availability
MVIEW is available for UNIX, and can be obtained from: MVIEW is available for UNIX, and can be obtained from:
ftp://ftp.merit.edu/net-research/mbone/mview/ ftp://ftp.merit.edu/net-research/mbone/mview/
Documentation is available as: Documentation is available as:
ftp://ftp.merit.edu/net-research/mbone/mviewdoc/ ftp://ftp.merit.edu/net-research/mbone/mviewdoc/
5.7.2. Multicast heartbeat 6.7.2. Multicast heartbeat
Author Author
Many and various Many and various
Description Description
Devices implementing the multicast heartbeat listen on a designated Devices implementing the multicast heartbeat listen on a designated
group. If traffic is not observed on the group for a specified group. If traffic is not observed on the group for a specified amount
amount of time, an SNMP trap is generated. This allows multicast of time, an SNMP trap is generated. This allows multicast monitoring
monitoring to be easily integrated into existing SNMP consoles. In to be easily integrated into existing SNMP consoles. In situations
situations where a shared-tree multicast routing protocol is used where a shared-tree multicast routing protocol is used (such as
(such as sparse-mode PIM or CBT), it is recommended that the heart- sparse-mode PIM or CBT), it is recommended that the heartbeat
beat generator be located close to the RP or core nodes, so as that generator be located close to the RP or core nodes, so as that loss
loss of the heartbeat will correlate closely with loss of connec- of the heartbeat will correlate closely with loss of connectivity to
tivity to the RP or core. Suitable heartbeat mechanisms include the RP or core. Suitable heartbeat mechanisms include SNTP, which
SNTP, which uses the group 224.0.1.1 (ntp.mcast.net) and UDP port uses the group 224.0.1.1 (ntp.mcast.net) and UDP port 123; and SAP,
123; and SAP, which uses the group 224.2.127.254 (sap.mcast.net) which uses the group 224.2.127.254 (sap.mcast.net) and UDP port 9875.
and UDP port 9875.
Example Example
For further information on SNTP, consult [1]. For further information on SNTP, consult [1].
Facilities used Facilities used
SNTP (for time-based heartbeats) SNTP (for time-based heartbeats)
SAP (for session announcement heartbeats) SAP (for session announcement heartbeats)
SNMP traps (for alerts) SNMP traps (for alerts)
Availability Availability
5.8. Network analysis tools
5.8.1. Dr. Watson, the Network Detective's Assistant (DWTNDA) 6.8. Network analysis tools
6.8.1. Dr. Watson, the Network Detective's Assistant (DWTNDA)
Author Author
Karl Auerbach, karl@cavebear.com Karl Auerbach, karl@cavebear.com
Description Description
DWTNDA is a general purpose troubleshooting tool with some IP mul- DWTNDA is a general purpose troubleshooting tool with some IP
ticast tools (in addition to a fair number of non-multicast tools). multicast tools (in addition to a fair number of non-multicast
For example it can watch IGMP "join" activity on a LAN and put up a tools). For example it can watch IGMP "join" activity on a LAN and
real-time display in tabular format. It can generate some test put up a real-time display in tabular format. It can generate some
packets, like IGMPv2 Leaves or Group Membership Requests. It can test packets, like IGMPv2 Leaves or Group Membership Requests. It can
generate and respond to multicast pings (icmp, udp, or snmp based.) generate and respond to multicast pings (icmp, udp, or snmp based.)
It will eventually acquire more sophisticated multicast facilities. It will eventually acquire more sophisticated multicast facilities.
Example Example
See http://www.cavebear.com/dwtnda/ for examples. See http://www.cavebear.com/dwtnda/ for examples.
Facilities used Facilities used
This is a troubleshooting tool, so it will typically respond to This is a troubleshooting tool, so it will typically respond to
packets that, strictly speaking, ought to go unanswered. packets that, strictly speaking, ought to go unanswered.
Availability Availability
DWTNDA runs on MS-DOS and Windows 95/98 and is free. Source is not DWTNDA runs on MS-DOS and Windows 95/98 and is free. Source is not
provided. See http://www.cavebear.com/dwtnda/ for various documents provided. See http://www.cavebear.com/dwtnda/ for various documents
and download information. and download information.
5.8.2. Mtap 6.8.2. Mtap
Author Author
Luis Fernando da Silva Barra, barra@ax.apc.org Luis Fernando da Silva Barra, barra@ax.apc.org
Michael Stanton, michael@omega.lncc.br Michael Stanton, michael@omega.lncc.br
Description Description
MTap is a tool for observing IP multicast packet traffic crossing a MTap is a tool for observing IP multicast packet traffic crossing a
subnet, normally an Ethernet. subnet, normally an Ethernet.
Each packet sent to an IP multicast group address (class D) is cap- Each packet sent to an IP multicast group address (class D) is
tured, and information is extracted concerning its origin, its captured, and information is extracted concerning its origin, its
size, and so forth. This information is summarized, permitting the size, and so forth. This information is summarized, permitting the
determination of the current network load resulting from multicast determination of the current network load resulting from multicast
traffic. Apart from global summaries, traffic information is traffic. Apart from global summaries, traffic information is
summarized by group and by source, permitting the determination of summarized by group and by source, permitting the determination of
the contribution of each group and each individual sender to global the contribution of each group and each individual sender to global
traffic. The data recorded are as follows: number of multicast traffic. The data recorded are as follows: number of multicast
packets and total multicast bytes passing through the network, load packets and total multicast bytes passing through the network, load
level, and date and time of the last packet received. level, and date and time of the last packet received.
As well as processing packets sent to a multicast address, MTap As well as processing packets sent to a multicast address, MTap also
also records separately multicast packets encapsulated in point-to- records separately multicast packets encapsulated in point-to-point
point packets. Thus we can also deal with traffic in DVMRP tunnels packets. Thus we can also deal with traffic in DVMRP tunnels between
between multicast routers, and tunnel traffic data are recorded in multicast routers, and tunnel traffic data are recorded in the same
the same way as for a group. way as for a group.
As well as recording the data. MTap also permits that individual As well as recording the data. MTap also permits that individual
packet data be exhibited in dump format at capture time, both for packet data be exhibited in dump format at capture time, both for
multicast packets and for tunneled packets. multicast packets and for tunneled packets.
In order to evaluate the impact which a group imposes on a subnet- In order to evaluate the impact which a group imposes on a
work, MTap can enter or leave a multicast group, using the IGMP subnetwork, MTap can enter or leave a multicast group, using the IGMP
protocol. Thus traffic can be observed for a group which has no protocol. Thus traffic can be observed for a group which has no other
other members on the subnetwork. members on the subnetwork.
In addition to passively observing and recording multicast traffic, In addition to passively observing and recording multicast traffic,
MTap has a notification mechanism, which sets off an alarm whenever MTap has a notification mechanism, which sets off an alarm whenever
user-specified load levels are exceeded, either globally, by group user-specified load levels are exceeded, either globally, by group or
or by tunnel. Notifications are also logged in a dedicated window. by tunnel. Notifications are also logged in a dedicated window.
Example Example
Further information on Mtap will be available from: Further information on Mtap will be available from:
http://www.inf.puc-rio.br/~michael/GERENTE/tools http://www.inf.puc-rio.br/~michael/GERENTE/tools
Facilities used Facilities used
Berkeley Packet Filter (BPF) Berkeley Packet Filter (BPF)
Availability Availability
MTap uses a window-based user interface, developed using Tcl/Tk, MTap uses a window-based user interface, developed using Tcl/Tk, and
and captures packets through the Berkeley Packet Filter (BPF). It captures packets through the Berkeley Packet Filter (BPF). It can
can thus be ported to different platforms. thus be ported to different platforms.
Mtap, which is still under development, has been ported to Linux Mtap, which is still under development, has been ported to Linux and
and Solaris; minor problems related to packet capture have still to Solaris; minor problems related to packet capture have still to be
be resolved for the Solaris version. When it is released, it will resolved for the Solaris version. When it is released, it will be
be available from: available from:
http://www.inf.puc-rio.br/~michael/GERENTE/tools http://www.inf.puc-rio.br/~michael/GERENTE/tools
6. References 7. References
[1] Mills, D., "Simple Network Time Protocol (SNTP) Version 4 for [1] Mills, D., "Simple Network Time Protocol (SNTP) Version 4 for IPv4,
IPv4, IPv6 and OSI", RFC 2030, October 1996. IPv6 and OSI", RFC 2030, October 1996.
[2] Fenner, W., "Internet Group Management Protocol, Version 2", RFC [2] Fenner, W., "Internet Group Management Protocol, Version 2", RFC
2236, November 1997. 2236, November 1997.
[3] McCloghrie, K., Farinacci, D., and D. Thaler, "Internet Group [3] McCloghrie, K., Farinacci, D., Thaler, D., "Internet Group
Management Protocol MIB", Internet draft (work in progress), draft- Management Protocol MIB", Internet draft (work in progress), draft-
ietf-idmr-igmp-mib-07.txt, July 1998. ietf-idmr-igmp-mib-10.txt, June 1999.
[4] M. Handley. "SAP: Session Announcement Protocol (Version 1)." [4] Handley, M., Jacobson, V., "SDP: Session Descripton Protocol
draft-ietf-mmusic-sap-02.ps, UCL, December, 1996. (Version 1)", RFC 2327, April 1998.
[5] McCloghrie, K., Farinacci, D., and D. Thaler, "IP Multicast Rout- [5] McCloghrie, K., Farinacci, D., Thaler D., "IP Multicast Routing
ing MIB", Internet draft (work in progress), draft-ietf-idmr-multi- MIB", Internet draft (work in progress), draft-ietf-idmr-multicast-
cast-routmib-07.txt, July 1998. routmib-10.txt, July 1999.
[6] McCloghrie, K., Farinacci, D., and D. Thaler, "Protocol Indepen- [6] McCloghrie, K., Farinacci, D., Thaler, D., "Protocol Independent
dent Multicast MIB", Internet draft (work in progress), draft-ietf- Multicast MIB", Internet draft (work in progress), draft-ietf-idmr-
idmr-pim-mib-05.txt, July 1998. pim-mib-07.txt, July 1999.
[7] Thaler, D., "Distance Vector Multicasting Routing Protocol MIB", [7] Thaler, D., "Distance Vector Multicasting Routing Protocol MIB",
Internet draft (work in progress), draft-ietf-idmr-dvmrp-mib-03.txt, Internet draft (work in progress), draft-thaler-dvmrp-mib-09.txt,
June 1996. May 1998.
[8] Fenner,W., and S. Casner, "A "traceroute" facility for IP Multi- [8] Fenner, W., Casner, S., "A "traceroute" facility for IP Multicast",
cast", Internet draft (work in progress), draft-ietf-idmr-traceroute- Internet draft (work in progress), draft-ietf-idmr-traceroute-
ipm-03.txt, August 1998. ipm-05.txt, June 1999.
[9] Rekhter, Y. et al., "Address Allocation for Private Internets", [9] Rekhter, Y. et al., "Address Allocation for Private Internets", RFC
RFC 1918, February, 1996. 1918, February, 1996.
7. Security Considerations 8. Security Considerations
SNMP-based monitoring tools require that the manager be provided SNMP-based monitoring tools require that the manager be provided access
access to the relevant MIBs. In order to limit security risks, such to the relevant MIBs. In order to limit security risks, such access will
access will typically be provided on a selective basis. For example, typically be provided on a selective basis. For example, the
the authentication and access control facilities in SNMP v3 can be authentication and access control facilities in SNMP v3 can be used to
used to limit access to authorized users. limit access to authorized users.
MBONE-mapping tools such as map-mbone should be used with care since MBONE-mapping tools such as map-mbone should be used with care since in
in flooding mode they can result in excessive load on multicast flooding mode they can result in excessive load on multicast routers.
routers.
Through use of RTP monitoring tools, it may be possible to obtain sen- Through use of RTP monitoring tools, it may be possible to obtain
sitive information on user viewing habits. In order to protect against sensitive information on user viewing habits. In order to protect
this, encryption technologies such as IPSEC can be used to provide against this, encryption technologies such as IPSEC can be used to
confidentiality. provide confidentiality.
8. Acknowledgments 9. Acknowledgments
Thanks to Karl Auerbach for the description of the Dr. Watson tool, Thanks to Karl Auerbach for the description of the Dr. Watson tool, and
and to Michael Stanton for the description of the Mtap tool. to Michael Stanton for the description of the Mtap tool.
9. Authors' Addresses 10. Authors' Addresses
Dave Thaler Dave Thaler
Microsoft Corporation Microsoft Corporation
One Microsoft Way One Microsoft Way
Redmond, WA 98052 Redmond, WA 98052
Phone: 425-703-8835 Phone: 425-703-8835
EMail: dthaler@microsoft.com EMail: dthaler@microsoft.com
Bernard Aboba Bernard Aboba
Microsoft Corporation Microsoft Corporation
One Microsoft Way One Microsoft Way
Redmond, WA 98052 Redmond, WA 98052
Phone: 425-936-6605 Phone: 425-936-6605
EMail: bernarda@microsoft.com EMail: bernarda@microsoft.com
10. Expiration Date 11. Full Copyright Statement
This memo is filed as <draft-ietf-mboned-mdh-01.txt>, and expires Copyright (C) The Internet Society (1999). All Rights Reserved.
May 1, 1999. This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it or
assist in its implmentation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are included
on all such copies and derivative works. However, this document itself
may not be modified in any way, such as by removing the copyright notice
or references to the Internet Society or other Internet organizations,
except as needed for the purpose of developing Internet standards in
which case the procedures for copyrights defined in the Internet
Standards process must be followed, or as required to translate it into
languages other than English. The limited permissions granted above are
perpetual and will not be revoked by the Internet Society or its
successors or assigns. This document and the information contained
herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE
INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF
12. Expiration Date
This memo is filed as <draft-ietf-mboned-mdh-03.txt>, and expires
March 1, 2000.
 End of changes. 

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