- IP Multicast Technology Overview
- Configuring Basic IP Multicast
- Configuring Basic IP Multicast in IPv6 Networks
- Using MSDP to Interconnect Multiple PIM-SM Domains
- PIM Allow RP
- Configuring Source Specific Multicast
- Implementing Multicast Stub Routing
- Tunneling to Connect Non-IP Multicast Areas
- HSRP Aware PIM
- Verifying IP Multicast Operation
- SNMP Traps for IP Multicast
- Monitoring and Maintaining IP Multicast
- Multicast User Authentication and Profile Support
- IPv6 Multicast: PIM Sparse Mode
- IPv6 Multicast: Static Multicast Routing for IPv6
- IPv6 Multicast: PIM Source-Specific Multicast
- IPv6 Source Specific Multicast Mapping
- IPv6 Multicast: Explicit Tracking of Receivers
- IPv6 Bidirectional PIM
- BFD Support for Multicast (PIM)
- IPv6 Multicast: Routable Address Hello Option
- PIMv6 Anycast RP Solution
- VRRP Aware PIM
- Finding Feature Information
- Prerequisites for Monitoring and Maintaining IP Multicast
- Information About Monitoring and Maintaining IP Multicast
- How to Monitor and Maintain IP Multicast
- Displaying Multicast Peers Packet Rates and Loss Information and Tracing a Path
- Displaying IP Multicast System and Network Statistics
- Clearing IP Multicast Routing Table, Caches, and Databases
- Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
- Advertising Multicast Multimedia Sessions Using SAP Listener
- Storing IP Multicast Headers
- Disabling Fast Switching of IP Multicast
- Configuration Examples for Monitoring and Maintaining IP Multicast
- Example Displaying Multicast Peers Packet Rates and Loss Information and Tracing a Path
- Example Displaying IP Multicast System and Network Statistics
- Example Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
- Example Advertising Multicast Multimedia Sessions Using SAP Listener
- Example Storing IP Multicast Headers
- Additional References
Monitoring and Maintaining IP Multicast
This module describes many ways to monitor and maintain an IP multicast network, such as
displaying which neighboring multicast routers are peering with the local router
displaying multicast packet rates and loss information
tracing the path from a source to a destination branch for a multicast distribution tree
displaying the contents of the IP multicast routing table, information about interfaces configured for PIM, the PIM neighbors discovered by the router, and contents of the IP fast-switching cache
clearing caches, tables, and databases
monitoring the delivery of IP multicast packets and being alerted if the delivery fails to meet certain parameters (IP multicast heartbeat)
using session description and announcement protocols and applications to assist the advertisement of multicast multimedia conferences and other multicast sessions and communicating the relevant session setup information to prospective participants (SAP listener support)
storing IP multicast packet headers in a cache and displaying them to find out information such as who is sending IP multicast packets to what groups and any multicast forwarding loops in your network
disabling fast switching of IP multicast in order to log debug messages
- Finding Feature Information
- Prerequisites for Monitoring and Maintaining IP Multicast
- Information About Monitoring and Maintaining IP Multicast
- How to Monitor and Maintain IP Multicast
- Configuration Examples for Monitoring and Maintaining IP Multicast
- Additional References
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Monitoring and Maintaining IP Multicast
Before performing the tasks in this module, you should be familiar with the concepts described in the “IP Multicast Technology Overview” module.
You must also have enabled IP multicast and have Protocol Independent Multicast (PIM) configured and running on your network. Refer to the “Configuring Basic IP Multicast” module.
Information About Monitoring and Maintaining IP Multicast
IP Multicast Delivery Using IP Multicast Heartbeat
The IP multicast heartbeat feature provides a way to monitor the status of IP multicast delivery and be informed when the delivery fails (via Simple Network Management Protocol [SNMP] traps).
IP Multicast Heartbeat
The IP Multicast Heartbeat feature enables you to monitor the delivery of IP multicast packets and to be alerted if the delivery fails to meet certain parameters.
Although you could alternatively use MRM to monitor IP multicast, you can perform the following tasks with IP multicast heartbeat that you cannot perform with MRM:
Generate an SNMP trap
Monitor a production multicast stream
When IP multicast heartbeat is enabled, the router monitors IP multicast packets destined for a particular multicast group at a particular interval. If the number of packets observed is less than a configured minimum amount, the router sends an SNMP trap to a specified network management station to indicate a loss of heartbeat exception.
The ip multicast heartbeat command does not create a heartbeat if there is no existing multicast forwarding state for group in the router. This command will not create a multicast forwarding state in the router. Use the ip igmp static-groupcommandon the router or on a downstream router to force forwarding of IP multicast traffic. Use the snmp-server host ipmulticast command to enable the sending of IP multicast traps to specific receiver hosts. Use the debug ip mhbeatcommand to debug the Multicast Heartbeat feature.
SNMP Notifications
A key feature of SNMP is the ability to generate notifications from an SNMP agent. These notifications do not require that requests be sent from the SNMP manager. Unsolicited (asynchronous) notifications can be generated as traps or inform requests. Traps are messages alerting the SNMP manager to a condition on the network. Inform requests (informs) are traps that include a request for confirmation of receipt from the SNMP manager. Notifications can indicate improper user authentication, restarts, the closing of a connection, loss of connection to a neighbor router, or other significant events.
Traps are less reliable than informs because the receiver does not send any acknowledgment when it receives a trap. The sender cannot determine if the trap was received. An SNMP manager that receives an inform request acknowledges the message with an SNMP response protocol data unit (PDU). If the manager does not receive an inform request, it does not send a response. If the sender never receives a response, the inform request can be sent again. Thus, informs are more likely to reach their intended destination.
However, traps are often preferred because informs consume more resources in the router and in the network. Unlike a trap, which is discarded as soon as it is sent, an inform request must be held in memory until a response is received or the request times out. Also, traps are sent only once, while an inform may be retried several times. The retries increase traffic and contribute to a higher overhead on the network. Thus, traps and inform requests provide a trade-off between reliability and resources. If it is important that the SNMP manager receives every notification, use inform requests. However, if you are concerned about traffic on your network or memory in the router and you need not receive every notification, use traps.
Session Announcement Protocol (SAP)
Session Announcement Protocol (SAP) listener support is needed to use session description and announcement protocols and applications to assist the advertisement of multicast multimedia conferences and other multicast sessions and to communicate the relevant session setup information to prospective participants.
Sessions are described by the Session Description Protocol (SDP), which is defined in RFC 2327. SDP provides a formatted, textual description of session properties (for example, contact information, session lifetime, and the media) being used in the session (for example, audio, video, and whiteboard) with their specific attributes such as time-to-live (TTL) scope, group address, and User Datagram Protocol (UDP) port number.
Many multimedia applications rely on SDP for session descriptions. However, they may use different methods to disseminate these session descriptions. For example, IP/TV relies on the web to disseminate session descriptions to participants. In this example, participants must know of a web server that provides the session information.
MBONE applications (for example, vic, vat, and wb) and other applications rely on multicast session information sent throughout the network. In these cases, SAP is used to transport the SDP session announcements. SAP Version 2 uses the well-known session directory multicast group 224.2.127.254 to disseminate SDP session descriptions for global scope sessions and group 239.255.255.255 for administrative scope sessions.
 Note | The Session Directory (SDR) application is commonly used to send and receive SDP/SAP session announcements. |
How to Monitor and Maintain IP Multicast
- Displaying Multicast Peers Packet Rates and Loss Information and Tracing a Path
- Displaying IP Multicast System and Network Statistics
- Clearing IP Multicast Routing Table, Caches, and Databases
- Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
- Advertising Multicast Multimedia Sessions Using SAP Listener
- Storing IP Multicast Headers
- Disabling Fast Switching of IP Multicast
Displaying Multicast Peers Packet Rates and Loss Information and Tracing a Path
Monitor IP multicast routing when you want to know which neighboring multicast routers are peering with the local router, what the multicast packet rates and loss information are, or when you want to trace the path from a source to a destination branch for a multicast distribution tree.
1.
enable
2.
mrinfo
[host-name | host-address] [source-address | interface]
3.
mstat
{source-name | source-address} [destination-name | destination-address] [group-name | group-address]
4.
mtrace
{source-name | source-address} [destination-name | destination-address] [group-name | group-address]
DETAILED STEPS
Displaying IP Multicast System and Network Statistics
Display IP multicast system statistics to show the contents of the IP multicast routing table, information about interfaces configured for PIM, the PIM neighbors discovered by the router, contents of the IP fast-switching cache, and the contents of the circular cache header buffer.
1.
enable
2.
ping
[group-name | group-address]
3.
show
ip
mroute
[group-address | group-name] [source-address | source-name] [type number] [summary] [count] [active kbps]
4.
show
ip
pim
interface
[type number] [df | count] [rp-address] [detail]
5.
show
ip
pim
neighbor
[type number]
6.
show
ip
mcache
[group-address | group-name] [source-address | source-name]
7.
show
ip
mpacket
[group-address | group-name] [source-address | source-name] [detail]
8.
show
ip
pim
rp
[mapping | metric] [rp-address]
9.
show
ip
rpf
{source-address | source-name} [metric]
DETAILED STEPS
Clearing IP Multicast Routing Table, Caches, and Databases
Clear IP multicast caches and tables to delete entries from the IP multicast routing table, the Auto-RP cache, the IGMP cache, and the caches of Catalyst switches. When these entries are cleared, the information is refreshed by being relearned, thus eliminating any incorrect entries.
1.
enable
2.
clear
ip
mroute
{* |
group-name
[source-name |
source-address]
|
group-address
[source-name |
source-address]}
3.
clear
ip
pim
auto-rp
rp-address
4.
clear
ip
mcache
5.
clear
ip
igmp
group
[group-name |
group-address |
interface-type
interface-number]
6.
clear
ip
cgmp
[interface-type
interface-number]
DETAILED STEPS
Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
1.
enable
2.
configure
terminal
3.
ip
multicast-routing
4.
snmp-server
host
{hostname | ip-address} [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string[udp-port port] [notification-type]
5.
snmp-server
enable
traps
ipmulticast
6.
ip
multicast
heartbeat
group-address
minimum-number
window-size
interval
DETAILED STEPS
Advertising Multicast Multimedia Sessions Using SAP Listener
Enable SAP listener support when you want to use session description and announcement protocols and applications to assist the advertisement of multicast multimedia conferences and other multicast sessions and to communicate the relevant session setup information to prospective participants.
1.
enable
2.
configure
terminal
3.
ip
sap
cache-timeout
minutes
4.
interface
type
number
5.
ip
sap
listen
6.
end
7.
clear
ip
sap
[group-address | “ session-name ”]
8.
show
ip
sap
[group-address | “ session-name ”| detail]
DETAILED STEPS
Storing IP Multicast Headers
You can store IP multicast packet headers in a cache and then display them to determine any of the following information:
Who is sending IP multicast packets to what groups
Interpacket delay
Duplicate IP multicast packets (if any)
Multicast forwarding loops in your network (if any)
Scope of the group
UDP port numbers
Packet length
Perform this task if you need any of the information listed above.
1.
enable
2.
configure
terminal
3.
ip
multicast
cache-headers
[rtp]
4.
exit
5.
show
ip
mpacket
[group-address | group-name] [source-address | source-name] [detail]
DETAILED STEPS
Disabling Fast Switching of IP Multicast
Disable fast switching if you want to log debug messages, because when fast switching is enabled, debug messages are not logged.
You might also want to disable fast switching, which places the router in process switching, if packets are not reaching their destinations. If fast switching is disabled and packets are reaching their destinations, then switching may be the cause.
Fast switching of IP multicast packets is enabled by default on all interfaces (including generic routing encapsulation [GRE] and DVMRP tunnels), with one exception: It is disabled and not supported over X.25 encapsulated interfaces. The following are properties of fast switching:
If fast switching is disabled on an incoming interface for a multicast routing table entry, the packet is sent at process level for all interfaces in the outgoing interface list.
If fast switching is disabled on an outgoing interface for a multicast routing table entry, the packet is process-level switched for that interface, but may be fast switched for other interfaces in the outgoing interface list.
When fast switching is enabled, debug messages are not logged.
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
no
ip
mroute-cache
DETAILED STEPS
Configuration Examples for Monitoring and Maintaining IP Multicast
- Example Displaying Multicast Peers Packet Rates and Loss Information and Tracing a Path
- Example Displaying IP Multicast System and Network Statistics
- Example Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
- Example Advertising Multicast Multimedia Sessions Using SAP Listener
- Example Storing IP Multicast Headers
Example Displaying Multicast Peers Packet Rates and Loss Information and Tracing a Path
The following is sample output from the mrinfo command:
Router# mrinfo 192.31.7.37 (labs-allcompany) [version cisco 12.3] [flags: PMSA]: 192.31.7.37 -> 192.31.7.34 (lab-southwest) [1/0/pim] 192.31.7.37 -> 192.31.7.47 (lab-northwest) [1/0/pim] 192.31.7.37 -> 192.31.7.44 (lab-southeast) [1/0/pim] 131.119.26.10 -> 131.119.26.9 (lab-northeast) [1/32/pim]
The following is sample output from the mstat command in user EXEC mode:
Router> mstat labs-in-china 172.16.0.1 224.0.255.255 Type escape sequence to abort. Mtrace from 172.16.0.0 to 172.16.0.10 via group 224.0.255.255 >From source (labs-in-china) to destination (labs-in-africa) Waiting to accumulate statistics...... Results after 10 seconds: Source Response Dest Packet Statistics For Only For Traffic 172.16.0.0 172.16.0.10 All Multicast Traffic From 172.16.0.0 | __/ rtt 48 ms Lost/Sent = Pct Rate To 224.0.255.255 v / hop 48 ms --------------------- -------------------- 172.16.0.1 labs-in-england | ^ ttl 1 v | hop 31 ms 0/12 = 0% 1 pps 0/1 = --% 0 pps 172.16.0.2 172.16.0.3 infolabs.com | ^ ttl 2 v | hop -17 ms -735/12 = --% 1 pps 0/1 = --% 0 pps 172.16.0.4 172.16.0.5 infolabs2.com | ^ ttl 3 v | hop -21 ms -678/23 = --% 2 pps 0/1 = --% 0 pps 172.16.0.6 172.16.0.7 infolabs3.com | ^ ttl 4 v | hop 5 ms 605/639 = 95% 63 pps 1/1 = --% 0 pps 172.16.0.8 172.16.0.9 infolabs.cisco.com | \__ ttl 5 v \ hop 0 ms 4 0 pps 0 0 pps 172.16.0.0 172.16.0.10 Receiver Query Source
The following is sample output from the mtrace command in user EXEC mode:
Router> mtrace 172.16.0.0 172.16.0.10 239.254.254.254 Type escape sequence to abort. Mtrace from 172.16.0.0 to 172.16.0.10 via group 239.254.254.254 From source (?) to destination (?) Querying full reverse path... 0 172.16.0.10 -1 172.16.0.8 PIM thresh^ 0 0 ms -2 172.16.0.6 PIM thresh^ 0 2 ms -3 172.16.0.5 PIM thresh^ 0 894 ms -4 172.16.0.3 PIM thresh^ 0 893 ms -5 172.16.0.2 PIM thresh^ 0 894 ms -6 172.16.0.1 PIM thresh^ 0 893 ms
Example Displaying IP Multicast System and Network Statistics
show ip mroute
The following is sample output from the show ip mroute command for a router operating in sparse mode:
Router# show ip mroute
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel,
Y - Joined MDT-data group, y - Sending to MDT-data group
Timers: Uptime/Expires
Interface state: Interface, Next-Hop, State/Mode
(*, 224.0.255.3), uptime 5:29:15, RP is 192.168.37.2, flags: SC
Incoming interface: Tunnel0, RPF neighbor 10.3.35.1, Dvmrp
Outgoing interface list:
Ethernet0, Forward/Sparse, 5:29:15/0:02:57
(192.168.46.0/24, 224.0.255.3), uptime 5:29:15, expires 0:02:59, flags: C
Incoming interface: Tunnel0, RPF neighbor 10.3.35.1
Outgoing interface list:
Ethernet0, Forward/Sparse, 5:29:15/0:02:57
show ip pim interface
The following is sample output from the show ip pim interface command when an interface is specified:
Router# show ip pim interface Ethernet1/0
Address Interface Ver/ Nbr Query DR DR
Mode Count Intvl Prior
172.16.1.4 Ethernet1/0 v2/S 1 100 ms 1 172.16.1.4
show ip mcache
The following is sample output from the show ip mcache privileged EXEC command when multicast distributed switching (MDS) is in effect:
Router# show ip mcache IP Multicast Fast-Switching Cache (*, 239.2.3.4), Fddi3/0/0, Last used: mds Tunnel3 MAC Header: 5000602F9C150000603E473F60AAAA030000000800 (Fddi3/0/0) Tunnel0 MAC Header: 5000602F9C150000603E473F60AAAA030000000800 (Fddi3/0/0) Tunnel1 MAC Header: 5000602F9C150000603E473F60AAAA030000000800 (Fddi3/0/0)
show ip mpacket
The following is sample output from the show ip mpacket command with the group-name argument:
Router# show ip mpacket smallgroup IP Multicast Header Cache - entry count:6, next index: 7 Key: id/ttl timestamp (name) source group D782/117 206416.908 (company1.company.com) 192.168.228.10 224.5.6.7 7302/113 206417.908 (school.edu) 172.16.2.17 224.5.6.7 6CB2/114 206417.412 (company2.company.com) 172.16.19.40 224.5.6.7 D782/117 206417.868 (company1.company.com) 192.168.228.10 224.5.6.7 E2E9/123 206418.488 (company3.com) 239.1.8.10 224.5.6.7 1CA7/127 206418.544 (company4.company.com) 192.168.6.10 224.5.6.7
The following is sample output from the show ip pim rp command:
Router# show ip pim rp Group:227.7.7.7, RP:10.10.0.2, v2, v1, next RP-reachable in 00:00:48
show ip pim rp
The following is sample output from the show ip pim rp command when the mapping keyword is specified:
Router# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent
Group(s) 227.0.0.0/8
RP 10.10.0.2 (?), v2v1, bidir
Info source:10.10.0.2 (?), via Auto-RP
Uptime:00:01:42, expires:00:00:32
Group(s) 228.0.0.0/8
RP 10.10.0.3 (?), v2v1, bidir
Info source:10.10.0.3 (?), via Auto-RP
Uptime:00:01:26, expires:00:00:34
Group(s) 229.0.0.0/8
RP 10.10.0.5 (mcast1.cisco.com), v2v1, bidir
Info source:10.10.0.5 (mcast1.cisco.com), via Auto-RP
Uptime:00:00:52, expires:00:00:37
Group(s) (-)230.0.0.0/8
RP 10.10.0.5 (mcast1.cisco.com), v2v1, bidir
Info source:10.10.0.5 (mcast1.cisco.com), via Auto-RP
Uptime:00:00:52, expires:00:00:37
The following is sample output from the show ip pim rp command when the metric keyword is specified:
Router# show ip pim rp metric RP Address Metric Pref Metric Flags RPF Type Interface 10.10.0.2 0 0 L unicast Loopback0 10.10.0.3 90 409600 L unicast Ethernet3/3 10.10.0.5 90 435200 L unicast Ethernet3/3
show ip rpf
The following is sample output from the show ip rpf command:
Router# show ip rpf 172.16.10.13 RPF information for host1 (172.16.10.13) RPF interface: BRI0 RPF neighbor: sj1.cisco.com (172.16.121.10) RPF route/mask: 172.16.0.0/255.255.0.0 RPF type: unicast RPF recursion count: 0 Doing distance-preferred lookups across tables
The following is sample output from the show ip rpfcommand when the metrickeyword is specified:
Router# show ip rpf 172.16.10.13 metric RPF information for host1.cisco.com (172.16.10.13) RPF interface: BRI0 RPF neighbor: neighbor.cisco.com (172.16.121.10) RPF route/mask: 172.16.0.0/255.255.0.0 RPF type: unicast RPF recursion count: 0 Doing distance-preferred lookups across tables Metric preference: 110 Metric: 11
Example Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
The following example shows how to monitor IP multicast packets forwarded through this router to group address 244.1.1.1. If no packet for this group is received in a 10-second interval, an SNMP trap will be sent to the SNMP management station with the IP address of 224.1.0.1.
! ip multicast-routing ! snmp-server host 224.1.0.1 traps public snmp-server enable traps ipmulticast ip multicast heartbeat ethernet0 224.1.1.1 1 1 10
Example Advertising Multicast Multimedia Sessions Using SAP Listener
The following example enables a router to listen to session directory announcements and changes the SAP cache timeout to 30 minutes.
ip multicast routing ip sap cache-timeout 30 interface loopback 0 ip address 10.0.0.51 255.255.255.0 ip pim sparse-dense mode ip sap listen
The following is sample output from the show ip sap command for a session using multicast group 224.2.197.250:
Router# show ip sap 224.2.197.250
SAP Cache - 198 entries
Session Name: Session1
Description: This broadcast is brought to you courtesy of Name1.
Group: 0.0.0.0, ttl: 0, Contiguous allocation: 1
Lifetime: from 10:00:00 PDT Jul 4 1999 until 10:00:00 PDT Aug 1 1999
Uptime: 4d05h, Last Heard: 00:01:40
Announcement source: 128.102.84.134
Created by: sample 3136541828 3139561476 IN IP4 128.102.84.134
Phone number: Sample Digital Video Lab (555) 555-5555
Email: email1 <name@email.com>
URL: http://url.com/
Media: audio 20890 RTP/AVP 0
Media group: 224.2.197.250, ttl: 127
Attribute: ptime:40
Media: video 62806 RTP/AVP 31
Media group: 224.2.190.243, ttl: 127
Example Storing IP Multicast Headers
The following is sample output from the show ip mpacket command for the group named “smallgroup.”
Router# show ip mpacket smallgroup IP Multicast Header Cache - entry count:6, next index: 7 Key: id/ttl timestamp (name) source group D782/117 206416.908 (company1.company.com) 192.168.228.10 224.5.6.7 7302/113 206417.908 (school.edu) 172.16.2.17 224.5.6.7 6CB2/114 206417.412 (company2.company.com) 172.16.19.40 224.5.6.7 D782/117 206417.868 (company1.company.com) 192.168.228.10 224.5.6.7 E2E9/123 206418.488 (company3.com) 239.1.8.10 224.5.6.7 1CA7/127 206418.544 (company4.company.com) 192.168.6.10 224.5.6.7
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
Cisco IOS IP SLAs commands |
Standards and RFCs
|
Standard/RFC |
Title |
|---|---|
|
RFC 2934 |
Protocol Independent Multicast for IPv4 MIB |
MIBs
|
MIB |
MIBs Link |
|---|---|
|
To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feedback