- Finding Feature Information
- Prerequisites for Monitoring and Maintaining IP Multicast
- Information About Monitoring and Maintaining 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 or Caches
- Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
- Advertising Multicast Multimedia Sessions Using SAP Listener
- Disabling Fast Switching of IP Multicast
- Enabling PIM MIB Extensions for IP Multicast
- 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
- Displaying IP Multicast System and Network Statistics Example
- Enabling PIM MIB Extensions for IP Multicast Example
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
- using managed objects to remotely monitor and configure PIM using Simple Network Management Protocol (SNMP)
- 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
- Feature Information for Monitoring and Maintaining IP Multicast
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see 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 document.
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 Heartbeat
- Session Announcement Protocol (SAP)
- PIM MIB Extensions for SNMP Traps for IP Multicast
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.
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. |
PIM MIB Extensions for SNMP Traps for IP Multicast
Protocol Independent Multicast (PIM) is an IP multicast routing protocol used for routing multicast data packets to multicast groups. RFC 2934 defines the PIM MIB for IPv4, which describes managed objects that enable users to remotely monitor and configure PIM using Simple Network Management Protocol (SNMP).
PIM MIB extensions introduce the following new classes of PIM notifications:
- neighbor-change--This notification results from the following conditions:
- A router's PIM interface is disabled or enabled (using the ip pim command in interface configuration mode)
- A router's PIM neighbor adjacency expires (defined in RFC 2934)
- rp-mapping-change--This notification results from a change in the rendezvous point (RP) mapping information due to either Auto-RP messages or bootstrap router (BSR) messages.
- invalid-pim-message--This notification results from the following conditions:
- An invalid (*, G) Join or Prune message is received by the device (for example, when a router receives a Join or Prune message for which the RP specified in the packet is not the RP for the multicast group)
- An invalid PIM register message is received by the device (for example, when a router receives a register message from a multicast group for which it is not the RP)
Benefits of PIM MIB Extensions
PIM MIB extensions:
- Allow users to identify changes in the multicast topology of their network by detecting changes in the RP mapping.
- Provide traps to monitor the PIM protocol on PIM-enabled interfaces.
- Help users identify routing issues when multicast neighbor adjacencies expire on a multicast interface.
- Enable users to monitor RP configuration errors (for example, errors due to flapping in dynamic RP allocation protocols like Auto-RP).
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 or Caches
- Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
- Advertising Multicast Multimedia Sessions Using SAP Listener
- Disabling Fast Switching of IP Multicast
- Enabling PIM MIB Extensions for 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.
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.
DETAILED STEPS
Clearing IP Multicast Routing Table or Caches
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.
DETAILED STEPS
Monitoring IP Multicast Delivery Using IP Multicast Heartbeat
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.
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.
DETAILED STEPS
Enabling PIM MIB Extensions for IP Multicast
Perform this task to enable PIM MIB extensions for IP multicast.
DETAILED STEPS
Configuration Examples for Monitoring and Maintaining IP Multicast
- 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
- Displaying IP Multicast System and Network Statistics Example
- Enabling PIM MIB Extensions for IP Multicast Example
Displaying IP Multicast System and Network Statistics Example
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
Monitoring IP Multicast Delivery Using IP Multicast Heartbeat Example
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 224.1.1.1 1 1 10
Advertising Multicast Multimedia Sessions Using SAP Listener Example
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
Displaying IP Multicast System and Network Statistics Example
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:
GigabitEthernet0, 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:
GigabitEthernet0, 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 GigabitEthernet1/0/0
Address Interface Ver/ Nbr Query DR DR
Mode Count Intvl Prior
172.16.1.4 GigabitEthernet1/0/0 v2/S 1 100 ms 1 172.16.1.4
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 GigabitEthernet3/3/0
10.10.0.5 90 435200 L unicast GigabitEthernet3/3/0
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
Enabling PIM MIB Extensions for IP Multicast Example
The following example shows how to configure a router to generate notifications indicating that a PIM interface of the router has been enabled. The first line configures PIM traps to be sent as SNMP v2c traps to the host with IP address 10.0.0.1. The second line configures the router to send the neighbor-change class of trap notification to the host.
snmp-server host 10.0.0.1 traps version 2c public pim snmp-server enable traps pim neighbor-change interface ethernet0/0 ip pim sparse-dense-mode
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
IP multicast SNMP notifications |
" Configuring SNMP Support " module |
IP multicast commands: complete command syntax, command mode, defaults, usage guidelines, and examples |
Cisco IOS IP Multicast Command Reference |
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: |
RFCs
RFC |
Title |
---|---|
RFC 2934 |
Protocol Independent Multicast for IPv4 MIB |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
Feature Information for Monitoring and Maintaining IP Multicast
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
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.
Table 1 | Feature Information for Monitoring and Maintaining IP Multicast |
Feature Names |
Releases |
Feature Configuration Information |
---|---|---|
PIM MIB Extensions |
Cisco IOS XE Release 2.1 |
Protocol Independent Multicast (PIM) is an IP multicast routing protocol used for routing multicast data packets to multicast groups. RFC 2934 defines the PIM for IPv4 MIB, which describes managed objects that enable users to remotely monitor and configure PIM using Simple Network Management Protocol (SNMP). |
Multicast Heartbeat |
Cisco IOS XE Release 2.1 |
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). |
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.