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This module describes many ways to monitor and maintain an IP multicast network, such as
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.
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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:
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) 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. |
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:
PIM MIB extensions:
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.
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.
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.
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.
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:
Perform this task to enable PIM MIB extensions for IP multicast.
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
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
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
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
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
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
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
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
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 |
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: |
RFC |
Title |
---|---|
RFC 2934 |
Protocol Independent Multicast for IPv4 MIB |
Description |
Link |
---|---|
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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). |
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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.