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Multicast Tool and Utility Commands on Cisco ASR 9000 Series Router
mrinfo
To query neighboring multicast routers peering with the local router, use the mrinfo command in EXEC mode.
Syntax Description
ipv4
(Optional) Specifies IPv4 address prefixes.
host-address
Can be either the Domain Name System (DNS) name or IP address of a multicast router entered in A.B.C.D format.
Note If omitted, the router queries itself.
source-address
(Optional) Source address used on multicast routing information (mrinfo) requests. If omitted, the source is based on the outbound interface for the destination.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The mrinfo command determines which neighboring multicast routers are peering with a multicast router.
You can query a multicast router with this command. The output format is identical to the multicast routed version of Distance Vector Multicast Routing Protocol (DVMRP). (The mrouted software is the UNIX software that implements DVMRP.)
Task ID
Examples
The following is sample output from the mrinfo command. The first line shows the multicast configuration with version number and flags Parent Multicast Agent (PMA). The flags mean that the configuration is prune capable, mtrace capable, and SNMP capable. For each neighbor of the queried multicast router, the IP address of the queried router is displayed, followed by the IP address of the neighbor. The metric (cost of connect) and the threshold (multicast time to live) are displayed. Other information is available, such as whether this router is
RP/0/RSP0/CPU0:router# mrinfo 192.168.50.1 192.168.50.1 [version 0.37.0] [flags: PMA]: 172.16.1.1 -> 172.16.1.1 [1/0/pim/querier/leaf] 172.16.2.2 -> 172.16.2.2 [1/0/pim/querier/leaf] 192.168.50.1 -> 192.168.50.1 [1/0/pim/querier] 192.168.50.1 -> 192.168.50.101 [1/0/pim/querier] 192.168.40.101 -> 192.168.40.1 [1/0/pim] 192.168.40.101 -> 192.168.40.101 [1/0/pim]mtrace
To trace the path from a source to a destination branch for a multicast distribution tree, use the mtrace command in EXEC mode.
Syntax Description
ipv4
(Optional) Specifies IPv4 address prefixes.
source
(Optional) Domain Name System (DNS) name or the IP address of the multicast-capable source. This is a unicast address of the beginning of the path to be traced.
destination
(Optional) DNS name or address of the unicast destination. If omitted, the mtrace starts from the system where the command originated.
group
(Optional) DNS name or multicast address of the group to be traced. Default address is 224.2.0.1 (the group used for MBONE Audio). When address 0.0.0.0 is used, the software invokes a weak mtrace. A weak mtrace is one that follows the Reverse Path Forwarding (RPF) path to the source, regardless of whether any router along the path has multicast routing table state.
ttl
(Optional) Time-to-live (TTL) threshold for a multicast trace request.
Range is 1 to 255 router hops.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The trace request generated by the mtrace command is multicast to the multicast group to find the last-hop router to the specified destination. The trace follows the multicast path from destination to source by passing the mtrace request packet using unicast to each hop. Responses are unicast to the querying router by the first-hop router to the source. This command allows you to isolate multicast routing failures.
If no arguments are entered, the router interactively prompts you for them.
This command is identical in function to the UNIX version of mtrace.
Task ID
Examples
The following is sample output from the mtrace command:
RP/0/RSP0/CPU0:router# mtrace 172.16.1.0 172.16.1.10 239.254.254.254 Type escape sequence to abort. Mtrace from 172.16.1.0 to 172.16.1.10 via group 239.254.254.254 From source (?) to destination (?) Querying full reverse path... Switching to hop-by-hop: 0 172.16.1.10 -1 172.17.20.101 PIM Reached RP/Core [172.16.1.0/24] -2 172.18.10.1 PIM [172.16.1.0/32] -3 172.16.1.0 PIM [172.16.1.0/32]sap cache-timeout
To limit how long a Session Announcement Protocol (SAP) cache entry stays active in the cache, use the sap cache-timeout command in global configuration mode. To return to the default behavior, use the no form of this command.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The sap cache-timeout command defines how long session announcements are cached by the router. Active session announcements are periodically re-sent by the originating site, refreshing the cached state in the router. The minimum interval between announcements for a single group is 5 minutes. Setting the cache timeout to a value less than 30 minutes is not recommended. Set the cache timeout to 0 to keep entries in the cache indefinitely.
Task ID
sap listen
To configure the Session Announcement Protocol (SAP) designated router (SDR) listener on a group address, use the sap listen command in global configuration mode. To return to the default behavior, use the no form of this command.
Syntax Description
ip-address
(Optional) Group IP address for an address range.
name
(Optional) Name of a prefix for an address range.
Command Default
When no group address is configured, the SDR listener is configured on the global SAP announcement group (224.2.127.254).
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The sap listen command configures an SDR listener that listens to SAP announcements on the configured group address. The group IP address can be any group in the range from 224.2.128.0 to 224.2.255.255.
Task ID
Examples
The following example configures an SDR listener for group on IP address 224.2.127.254:
RP/0/RSP0/CPU0:router(config)# sap listen 224.2.127.254show sap
To display the Session Announcement Protocol (SAP) sessions learned on the configured multicast groups, use the show sap command in EXEC mode.
Syntax Description
ipv4
(Optional) Specifies IPv4 address prefixes.
group-address
(Optional) Group IP address or name of the session that is learned.
session-name
(Optional) Session name.
detail
(Optional) Provides more SAP information.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The show sap command displays the sessions learned on the configured multicast groups. The detail keyword displays verbose session information.
Use the sap listen command to configure the SDR listener on a group IP address.
Task ID
Examples
The following is sample output from the show sap command. Information is summarized and shows one entry.
RP/0/RSP0/CPU0:router# show sap Sap Session Table Summary Cisco Systems, Inc Src: 192.168.30.101, Dst: 224.2.127.254, Last Heard: 00:00:23 Total Entries : 1
This table describes the significant fields shown in the display.
Table 1 show sap Field DescriptionsField
Description
Src
IP address of the host from which this session announcement was received.
Dst
Destination IP multicast group address where the announcement was sent.
Last Heard
Time (in hours, minutes, and seconds) when SAP announcements were last heard from the source.
Total Entries
Total number of entries displayed.
The following is sample output from the show sap command with the detail keyword specified for the SAP session, Cisco Systems, Inc.
RP/0/RSP0/CPU0:router# show sap detail Sap Session Table Session Name: Cisco Systems, Inc Description: IPTV Streaming Video Group: 225.225.225.1 TTL: 2 Announcement source: 192.30.30.101, Destination: 224.2.127.254 Created by: - 0050c200aabb 9 IN IP4 10.10.176.50 Session Permanent Attribute: packetsize:4416 Attribute: packetformat:RAW Attribute: mux:m1s Attribute: keywds: Attribute: author:Cisco Systems, Inc Attribute: copyright:Cisco Systems, Inc Media : video, Transport Protocol : udp, Port : 444 Total Entries : 1
This table describes the significant fields shown in the display.
Table 2 show sap detail Field DescriptionsField
Description
Session Name
Descriptive name of the SAP session.
Description
An expanded description of the session.
Group
IP multicast group addresses used for this session.
Announcement source
IP address of the host from which this session announcement was received.
Destination
Destination IP multicast group address that the announcement was sent to.
Created by
Information for identifying and tracking the session announcement.
Attribute
Indicates attributes specific to the session.
Media
Indicates the media type (audio, video, or data), transport port that the media stream is sent to, transport protocol used for these media (common values are User Datagram Protocol [UDP] and Real-Time Transport Protocol [RTP]/AVP), and list of media formats that each media instance can use. The first media format is the default format. Format identifiers are specific to the transport protocol used.