Table Of Contents
ip dvmrp routehog-notification
ip igmp last-member-query-count
ip igmp last-member-query-interval
ip igmp query-max-response-time
ip multicast default-rpf-distance
ip cgmp
To enable Cisco Group Management Protocol (CGMP) on an interface of a router connected to a Cisco Catalyst 5000 family switch, use the ip cgmp command in interface configuration mode. To disable CGMP routing, use the no form of this command.
ip cgmp [proxy | router-only]
no ip cgmp
Syntax Description
proxy
(Optional) Enables CGMP and the CGMP proxy function.
router-only
(Optional) Enables the router to send only CGMP self-join and CGMP self-leave messages.
Defaults
CGMP is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
When enabled on an interface, this command triggers a CGMP join message. This command should be used only on 802 media (that is, Ethernet, FDDI, or Token Ring) or ATM. When a no ip cgmp command is issued, a triggered CGMP leave message is sent for the MAC address on the interface for group 0000.0000.0000 (all groups). CGMP can run on an interface only if Protocol Independent Multicast (PIM) is configured on the same interface.
A Cisco router will send CGMP join messages in response to receiving Internet Group Management Protocol (IGMP) reports from IGMP-capable members. Only the CGMP querier Cisco router sends these CGMP join messages on behalf of hosts.
The ip cgmp router-only command enables the routers in a VLAN to send only CGMP self-join and CGMP self-leave messages—no other types of CGMP messages will be sent. This feature allows other CGMP-capable routers to learn about multicast router ports. If the ip cgmp router-only command is not available on any of the external routers in the network, the ip cgmp command can be used instead. Issuing the ip cgmp command on a router enables that router to send CGMP self-join and CGMP self-leave messages as well as other types of CGMP messages.
When the proxy keyword is specified, the CGMP proxy function is also enabled. That is, any router that is not CGMP-capable will be advertised by the proxy router. The proxy router advertises the existence of other non-CGMP-capable routers by sending a CGMP join message with the MAC address of the non-CGMP-capable router and a group address of 0000.0000.0000.
Initially supported is Distance Vector Multicast Routing Protocol (DVMRP) proxying. If a DVMRP report is received from a router that is not a PIM router, a Cisco IGMP querier will advertise the MAC address of the DVMRP router in a CGMP join message with the group address 0000.0000.0000.
To perform CGMP proxy, a Cisco router must be the IGMP querier. If you configure the ip cgmp proxy command, you must manipulate the IP addresses so that a Cisco router will be the IGMP querier, which might be the highest or lowest IP address, depending on which version of IGMP is being run on the network. An IGMP Version 2 querier is selected based on the lowest IP addressed router on the interface. An IGMP Version 1 querier is selected based on the multicast routing protocol used on the interface.
When multiple Cisco routers are connected to a switched network and the ip cgmp proxy command is needed, we recommend that all routers be configured in the following manner:
•
With the same CGMP option.
•
Examples
The following example enables CGMP:
ip cgmpThe following example enables CGMP and CGMP proxy:
ip cgmp proxyip dvmrp accept-filter
To configure an acceptance filter for incoming Distance Vector Multicast Routing Protocol (DVMRP) reports, use the ip dvmrp accept-filter command in interface configuration mode. To disable this filter, use the no form of this command.
ip dvmrp accept-filter access-list [distance | neighbor-list access-list]
no ip dvmrp accept-filter access-list [distance | neighbor-list access-list]
Syntax Description
Defaults
All destination reports are accepted with a distance of 0. Default settings accept reports from all neighbors.
Command Modes
Interface configuration
Command History
10.0
This command was introduced.
11.2
The neighbor-list keyword and access-list-number argument were added.
Usage Guidelines
Any sources that match the access list are stored in the DVMRP routing table with the distance argument.
The distance value is used to compare with the same source in the unicast routing table. The route with the lower distance (either the route in the unicast routing table or that in the DVMRP routing table) takes precedence when computing the Reverse Path Forwarding (RPF) interface for a source of a multicast packet.
By default, the administrative distance for DVMRP routes is 0, which means that they always take precedence over unicast routing table routes. If you have two paths to a source, one through unicast routing (using Protocol Independent Multicast [PIM] as the multicast routing protocol) and another path using DVMRP (unicast and multicast routing), and if you want to use the PIM path, use the ip dvmrp accept-filter command to increase the administrative distance for DVMRP routes.
Examples
The following example shows how to apply an access list such that the RPF interface used to accept multicast packets will be through an Enhanced Interior Gateway Routing Protocol (IGRP)/PIM path. The Enhanced IGRP unicast routing protocol has a default administrative distance of 90.
ip dvmrp accept-filter 1 100access-list 1 permit 0.0.0.0 255.255.255.255The following example applies access list 57 to the interface and sets a distance of 4:
access-list 57 permit 172.16.0.0 0.0.255.255access-list 57 permit 192.168.0.0 0.0.0.255access-list 57 deny 10.0.0.0 255.255.255.255ip dvmrp accept-filter 57 4Related Commands
ip dvmrp auto-summary
To enable Distance Vector Multicast Routing Protocol (DVMRP) automatic summarization if it was disabled, use the ip dvmrp auto-summary command in interface configuration mode. To disable the feature, use the no form of this command.
ip dvmrp auto-summary
no ip dvmrp auto-summary
Syntax Description
This command has no arguments or keywords.
Defaults
DVMRP automatic summarization is enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
DVMRP automatic summarization occurs when a unicast subnet route is collapsed into a classful network number route. This situation occurs when the subnet is a different network number than the IP address of the interface (or tunnel) over which the advertisement is sent. If the interface is unnumbered, the network number of the numbered interface the unnumbered interface points to is compared to the subnet.
Disable this feature if the information you want to send using the ip dvmrp summary-address command is the same as the information that would be sent using DVMRP automatic summarization.
Examples
The following example disables DVMRP automatic summarization:
no ip dvmrp auto-summaryRelated Commands
ip dvmrp summary-address
Configures a DVMRP summary address to be advertised out the interface.
ip dvmrp default-information
To advertise network 0.0.0.0 to Distance Vector Multicast Routing Protocol (DVMRP) neighbors on an interface, use the ip dvmrp default-information command in interface configuration mode. To prevent the advertisement, use the no form of this command.
ip dvmrp default-information {originate | only}
no ip dvmrp default-information {originate | only}
Syntax Description
originate
Specifies that other routes more specific than 0.0.0.0 may be advertised.
only
Specifies that no DVMRP routes other than 0.0.0.0 are advertised.
Defaults
Network 0.0.0.0 is not advertised to DVMRP neighbors on an interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command should be used only when the router is a neighbor to mrouted version 3.6 devices. The mrouted protocol is a public domain implementation of DVMRP.
You can use the ip dvmrp metric command with the ip dvmrp default-information command to tailor the metric used when advertising the default route 0.0.0.0. By default, metric 1 is used.
Examples
The following example configures the Cisco IOS software to advertise network 0.0.0.0, in addition to other networks, to DVMRP neighbors:
ip dvmrp default-information originateRelated Commands
ip dvmrp metric
Configures the metric associated with a set of destinations for DVMRP reports.
ip dvmrp metric
To configure the metric associated with a set of destinations for Distance Vector Multicast Routing Protocol (DVMRP) reports, use the ip dvmrp metric command in interface configuration mode. To disable this function, use the no form of this command.
ip dvmrp metric metric [route-map map-name] [mbgp] [mobile] [list access-list-number] [protocol process-id] | dvmrp]
no ip dvmrp metric metric [route-map map-name] [mbgp] [mobile] [list access-list-number] [protocol process-id] | dvmrp]
Syntax Description
Defaults
No metric value is preconfigured. Only directly connected subnets and networks are advertised to neighboring DVMRP routers.
Command Modes
Interface configuration
Command History
10.2
This command was introduced.
11.1
The route-map keyword was added.
11.1(20)CC
This mbgp keyword was added.
12.0(7)T
This mbgp keyword was added.
Usage Guidelines
When Protocol Independent Multicast (PIM) is configured on an interface and DVMRP neighbors are discovered, the Cisco IOS software sends DVMRP report messages for directly connected networks. The ip dvmrp metric command enables DVMRP report messages for multicast destinations that match the access list. Usually, the metric for these routes is 1. Under certain circumstances, you might want to tailor the metric used for various unicast routes. This command lets you configure the metric associated with a set of destinations for report messages sent out this interface.
You can use the access-list-number argument in conjunction with the protocol and process-id arguments to selectively list the destinations learned from a given routing protocol.
To display DVMRP activity, use the debug ip dvmrp command.
Examples
The following example connects a PIM cloud to a DVMRP cloud. Access list 1 permits the sending of DVMRP reports to the DVMRP routers advertising all sources in the 172.16.35.0 network with a metric of 1. Access list 2 permits all other destinations, but the metric of 0 means that no DVMRP reports are sent for these destinations.
access-list 1 permit 172.16.35.0 0.0.0.255access-list 1 deny 0.0.0.0 255.255.255.255access-list 2 permit 0.0.0.0 255.255.255.255interface tunnel 0ip dvmrp metric 1 list 1ip dvmrp metric 0 list 2The following example redistributes IPv4 multicast routes into DVMRP neighbors with a metric of 1:
interface tunnel 0ip dvmrp metric 1 mbgpRelated Commands
debug ip dvmrp
Displays information on DVMRP packets received and sent.
ip dvmrp accept-filter
Configures an acceptance filter for incoming DVMRP reports.
ip dvmrp metric-offset
To change the metrics of advertised Distance Vector Multicast Routing Protocol (DVMRP) routes and thus favor or not favor a certain route, use the ip dvmrp metric-offset command in interface configuration mode. To restore the default values, use the no form of this command.
ip dvmrp metric-offset [in | out] increment
no ip dvmrp metric-offset
Syntax Description
Defaults
If neither in nor out is specified, in is the default.
in: 1
out: 0Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to influence which routes are used, as you prefer. The DVMRP metric is in hop count.
Examples
The following example adds 10 to the incoming DVMRP reports:
ip dvmrp metric-offset 10ip dvmrp output-report-delay
To configure an interpacket delay of a Distance Vector Multicast Routing Protocol (DVMRP) report, use the ip dvmrp output-report-delay command in interface configuration mode. To restore the default values, use the no form of this command.
ip dvmrp output-report-delay milliseconds [burst]
no ip dvmrp output-report-delay milliseconds [burst]
Syntax Description
Defaults
milliseconds: 100 milliseconds
burst: 2 packetsCommand Modes
Interface configuration
Command History
Usage Guidelines
The delay is the number of milliseconds that elapse between transmissions of sets of packets that constitute a report. The number of packets in the set is determined by the burst value.
You might want to change the default values, depending on the CPU and buffering of the mrouted machine.
Examples
The following example sets the interpacket delay to 200 milliseconds and the burst size to 3 packets. Therefore, at the periodic DVMRP report interval, if six packets are built, three packets will be sent, then a delay of 200 milliseconds will occur, and then the next three packets will be sent.
ip dvmrp output-report-delay 200 3ip dvmrp reject-non-pruners
To configure the router so that it will not peer with a Distance Vector Multicast Routing Protocol (DVMRP) neighbor if that neighbor does not support DVMRP pruning or grafting, use the ip dvmrp reject-non-pruners command in interface configuration mode. To disable the function, use the no form of this command.
ip dvmrp reject-non-pruners
no ip dvmrp reject-non-pruners
Syntax Description
This command has no arguments or keywords.
Defaults
Routers peer with DVMRP neighbors that do not support DVMRP pruning or grafting.
Command Modes
Interface configuration
Command History
Usage Guidelines
By default, the router accepts all DVMRP neighbors as peers, regardless of their DVMRP capability or lack thereof.
Use this command to prevent a router from peering with a DVMRP neighbor if that neighbor does not support DVMRP pruning or grafting. If the router receives a DVMRP probe or report message without the Prune-Capable flag set, the router logs a syslog message and discards the message.
Note that this command prevents peering with neighbors only. If there are any nonpruning routers multiple hops away (downstream toward potential receivers) that are not rejected, then a nonpruning DVMRP network might still exist.
Examples
The following example configures the router not to peer with DVMRP neighbors that do not support pruning or grafting:
ip dvmrp reject-non-prunersip dvmrp routehog-notification
To change the number of Distance Vector Multicast Routing Protocol (DVMRP) routes allowed before a syslog warning message is issued, use the ip dvmrp routehog-notification command in global configuration mode. To restore the default value, use the no form of this command.
ip dvmrp routehog-notification route-count
no ip dvmrp routehog-notification
Syntax Description
route-count
Number of routes allowed before a syslog message is triggered. The default is 10,000 routes.
Defaults
10,000 routes
Command Modes
Global configuration
Command History
Usage Guidelines
This command configures how many DVMRP routes are accepted on each interface within an approximate 1-minute period before a syslog message is issued, warning that a route surge might be occurring. The warning is typically used to detect quickly when routers have been misconfigured to inject a large number of routes into the multicast backbone (MBONE).
The show ip igmp interface command displays a running count of routes. When the count is exceeded, an "*** ALERT ***" is appended to the line.
Examples
The following example lowers the threshold to 8000 routes:
ip dvmrp routehog-notification 8000Related Commands
show ip igmp interface
Displays multicast-related information about an interface.
ip dvmrp route-limit
To change the limit on the number of Distance Vector Multicast Routing Protocol (DVMRP) routes that can be advertised over an interface enabled to run DVMRP, use the ip dvmrp route-limit command in global configuration mode. To configure no limit, use the no form of this command.
ip dvmrp route-limit count
no ip dvmrp route-limit
Syntax Description
Defaults
count: 7000 routes
Command Modes
Global configuration
Command History
Usage Guidelines
Interfaces enabled to run DVMRP include a DVMRP tunnel, an interface where a DVMRP neighbor has been discovered, and an interface configured to run the ip dvmrp unicast-routing command.
The ip dvmrp route-limit command is automatically generated to the configuration file when at least one interface is enabled for multicast routing. This command is necessary to prevent misconfigured ip dvmrp metric commands from causing massive route injection into the multicast backbone (MBONE).
Examples
The following example changes the limit to 5000 DVMRP routes allowed to be advertised:
ip dvmrp route-limit 5000Related Commands
ip dvmrp metric
Configures the metric associated with a set of destinations for DVMRP reports.
ip dvmrp unicast-routing
Enables DVMRP unicast routing on an interface.
ip dvmrp summary-address
To configure a Distance Vector Multicast Routing Protocol (DVMRP) summary address to be advertised out the interface, use the ip dvmrp summary-address command in interface configuration mode. To remove the summary address, use the no form of this command.
ip dvmrp summary-address summary-address mask [metric value]
no ip dvmrp summary-address summary-address mask [metric value]
Syntax Description
Defaults
metric value: 1
Command Modes
Interface configuration
Command History
Usage Guidelines
If there is at least a single, more specific route in the unicast routing table that matches the specified address and mask arguments, the summary is advertised. Routes in the DVMRP routing table are not candidates for summarization.
When the metric keyword is specified, the summary is advertised with that metric value.
Multiple summary addresses can be configured on an interface. When multiple overlapping summary addresses are configured on an interface, the one with the longest mask takes preference.
Examples
The following example configures the DVMRP summary address 172.16.0.0 to be advertised out the interface:
ip dvmrp summary-address 172.16.0.0 255.255.0.0 metric 1Related Commands
ip dvmrp unicast-routing
To enable Distance Vector Multicast Routing Protocol (DVMRP) unicast routing on an interface, use the ip dvmrp unicast-routing command in interface configuration mode. To disable the feature, use the no form of this command.
ip dvmrp unicast-routing
no ip dvmrp unicast-routing
Syntax Description
This command has no arguments or keywords.
Defaults
DVMRP unicast routing on an interface is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
Enabling DVMRP unicast routing means that routes in DVMRP report messages are cached by the router in a DVMRP routing table. When Protocol Independent Multicast (PIM) is running, these routes may get preference over routes in the unicast routing table. This capability allows PIM to run on the multicast backbone (MBONE) topology when it is different from the unicast topology.
DVMRP unicast routing can run on all interfaces, including generic routing encapsulation (GRE) tunnels. On DVMRP tunnels, it runs by virtue of DVMRP multicast routing. This command does not enable DVMRP multicast routing among Cisco routers. However, if there is a DVMRP-capable multicast router, the Cisco router will do PIM and DVMRP multicast routing interaction.
Examples
The following example enables DVMRP unicast routing:
ip dvmrp unicast-routingRelated Commands
ip dvmrp route-limit
Changes the limit on the number of DVMRP routes that can be advertised over an interface enabled to run DVMRP.
ip igmp access-group
To control the multicast groups that hosts on the subnet serviced by an interface can join, use the ip igmp access-group command in interface configuration mode. To disable this control, use the no form of this command.
ip igmp access-group access-list
no ip igmp access-group access-list
Syntax Description
access-list
Number or name of a standard or extended IP access list. The access list can be a number from 1 to 99 for a standard access list, and 100 to 199 for an extended access list.
Defaults
All groups are allowed on an interface.
Command Modes
Interface configuration
Command History
10.0
This command was introduced.
12.3(7)T
Extended access list support was added.
Examples
In the following example, hosts serviced by Ethernet interface 0 can join the group 225.2.2.2 only:
access-list 1 225.2.2.2 0.0.0.0interface ethernet 0ip igmp access-group 1The following are examples of extended access lists.
The first part of the extended access list clause controls the source (multicast sender), and the second part of the extended access list clause controls the multicast group.
Deny all state for a group G
deny igmp any host Gpermit igmp any anyDeny all state for a source S
deny igmp host S anypermit igmp any anyPermit all state for a group G
permit igmp any host GPermit all state for a source S
permit igmp host S anyFilter a particular source for a group G
deny igmp host S host Gpermit igmp any host Gip igmp explicit-tracking
To enable explicit tracking of hosts, groups, and channels for IGMP Version 3 (IGMPv3), use the ip igmp explicit-tracking command in interface configuration mode. To disable this feature, use the no form of this command.
ip igmp explicit-tracking
no ip igmp explicit-tracking
Syntax Description
This command has no arguments or keywords.
Defaults
Explicit tracking of hosts, groups and channels for IGMPv3 is disabled.
Command Modes
Interface configuration
Command History
12.0(19)S
This command was introduced.
12.2(8)T
This command was integrated into Cisco IOS Release 12.2(8)T.
Usage Guidelines
This command can be configured on an interface only if IGMPv3 is first configured on the same interface. To configure IGMPv3, use the ip igmp version 3 command in interface configuration mode.
When explicit tracking is enabled on a router, the router can individually track the Internet Group Management Protocol (IGMP) membership state of all reporting hosts. This feature allows the router to achieve minimal leave latencies when hosts leave a multicast group or channel. To monitor IGMP membership of hosts, use the show ip igmp membership command in user EXEC or privileged EXEC mode.
When explicit tracking is enabled, the router uses more memory than if explicit tracking is disabled because the router must store the membership state of all hosts on the interface.
Examples
The following example shows a basic configuration for enabling IP multicast with Source Specific Multicast (SSM), IGMPv3, and explicit tracking:
ip multicast routinginterface ethernet 0description access network to desktop systemsip address 10.1.0.1 255.255.255.0ip pim sparse-dense-modeip mroute-cacheip igmp version 3ip igmp explicit-trackingip igmp v3liteip urdinterface ethernet 1description backbone interface !No hosts connectedip address 10.10.0.1 255.255.255.0ip pim sparse-dense-modeip mroute-cacheip pim ssm defaultRelated Commands
ip igmp version
Configures the version of IGMP that the router uses.
show ip igmp membership
Displays the IGMP membership information for multicast groups and (S, G) channels.
ip igmp helper-address
To cause the system to forward all Internet Group Management Protocol (IGMP) host reports and leave messages received on the interface to the specified IP address, use the ip igmp helper-address command in interface configuration mode. To disable such forwarding, use the no form of this command.
ip igmp helper-address ip-address
no ip igmp helper-address
Syntax Description
ip-address
IP address to which IGMP host reports and leave messages are forwarded. Specify the IP address of an interface on the central router.
Defaults
IGMP host reports and leave messages are not forwarded.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command and the ip pim neighbor-filter command together enable stub multicast routing. The IGMP host reports and leave messages are forwarded to the IP address specified. The reports are re-sent out the next hop interface toward the IP address, with the source address of that interface. This command enables a type of "dense-mode" join, allowing stub sites not participating in Protocol Independent Multicast (PIM) to indicate membership in IP multicast groups.
Examples
The following example enables stub multicast routing on Router A, which has an outgoing interface with IP address 10.0.0.1. Router B is a central router with an incoming interface with address 10.0.0.2. Access list 1 filters PIM messages from the source (stub Router A).
Router A Configuration
ip multicast-routingip pim dense-modeip igmp helper-address 10.0.0.2Router B Configuration
ip multicast-routingip pim dense-mode : or ip pim sparse-modeip pim neighbor-filter 1access-list 1 deny 10.0.0.1Related Commands
ip pim neighbor-filter
Prevents a router from participating in PIM (for example, to configure stub multicast routing).
ip igmp helper-address (UDL)
To configure Internet Group Management Protocol (IGMP) helpering as required for IGMP unidirectional link routing (UDLR), use the ip igmp helper-address command in interface configuration mode. To disable such report forwarding, use the no form of this command.
ip igmp helper-address udl interface-type interface-number
no ip igmp helper-address
Syntax Description
udl interface-type interface-number
Specifies the interface type and number of a unidirectional interface.
Defaults
No forwarding occurs.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is required on a downstream router on each interface connected to a potential multicast receiver. The command allows the downstream router to helper IGMP reports received from hosts to an upstream router connected to a unidirectional link (UDL) associated with the configured interface-type and interface-number arguments.
Examples
The following example configures a helper address on a downstream router:
ip multicast-routing!! Interface that receiver is attached to, configure for IGMP reports to be! helpered for the unidirectional interface.!interface ethernet 0description Forward IGMP reports from this interface to UDL querierip address 10.0.0.2 255.0.0.0ip pim sparse-dense-modeip igmp helper-address udl serial 0Related Commands
ip igmp proxy-service
Enables the mroute proxy service.
ip igmp unidirectional-link
Configures an interface to be unidirectional and enables it for IGMP UDLR.
ip igmp immediate-leave
To minimize the leave latency of Internet Group Management Protocol (IGMP) memberships when IGMP Version 2 is used and only one receiver host is connected to each interface, use the ip igmp immediate-leave command in global or interface configuration mode. To disable this feature, use the no form of this command.
ip igmp immediate-leave group-list access-list
no ip igmp immediate-leave
Syntax Description
group-list access-list
Specifies a standard access list number or name that defines multicast groups in which the immediate leave feature is enabled.
Defaults
This command is disabled.
Command Modes
Global configuration
Interface configurationCommand History
Usage Guidelines
You cannot configure this command in both interface and global configuration mode.
When this command is not configured, the router will send an IGMP group-specific query message upon receipt of an IGMP Version 2 (IGMPv2) group leave message. The router will stop forwarding traffic for that group only if no host replies to the query within the timeout period. The timeout period is determined by the ip igmp last-member-query-interval command and the IGMP robustness variable, which is defined by the IGMP specification. By default, the timeout period in Cisco IOS software is approximately 2.5 seconds.
If this command is configured, the router assumes that only one host has joined the group and stops forwarding the group's traffic immediately upon receipt of an IGMPv2 group leave message.
Global Configuration Mode
When this command is configured in global configuration mode, it applies to all IGMP-enabled interfaces. Any existing configuration of this command in interface configuration mode will be removed from the configuration. Also, any new configuration of this command in interface configuration mode will be ignored.
Interface Configuration Mode
When this command is configured in interface configuration mode, it applies to an individual interface. Configure this command on an interface if only one IGMP-enabled neighbor is connected to the interface. The neighbor can be either a host or switch running IGMP Snooping. When the ip igmp immediate-leave command is enabled on an interface, the router will not send IGMP group-specific host queries when an IGMP Version 2 leave group message is received from that interface. Instead, the router will immediately remove the interface from the IGMP cache for that group and send Protocol Independent Multicast (PIM) prune messages toward sources if this interface was the last one to join that group.
Examples
The following example shows how to enable the immediate leave feature on all interfaces for all multicast groups:
Router(config)# ip multicast-routingRouter(config)# ip igmp immediate-leave group-list all-groupsRouter(config)# interface ethernet 0Router(config-if)# ip address 10.0.10.1 255.255.255.0Router(config-if)# ip pim sparse-dense modeRouter(config-if)# exitRouter(config)# ip access-list standard all-groupsRouter(config)# permit 224.0.0.0 15.255.255.255The following example shows how to enable the immediate leave feature on an interface for a specific range of multicast groups. In this example, the router assumes that the tv-groups access list consists of groups that have only one host membership at a time per interface:
Router(config)# ip multicast-routingRouter(config)# interface ethernet 0Router(config-if)# ip address 10.0.10.1 255.255.255.0Router(config-if)# ip pim sparse-dense-modeRouter(config-if)# ip igmp immediate-leave group-list tv-groupsRouter(config-if)# exitRouter(config)# ip access-list standard tv-groupsRouter(config)# permit 239.192.20.0 0.0.0.255Related Commands
ip igmp last-member-query-interval
Configures the frequency at which the router sends IGMP group-specific host query messages.
ip igmp join-group
To have the router join a multicast group, use the ip igmp join-group command in interface configuration mode. To cancel membership in a multicast group, use the no form of this command.
ip igmp join-group group-address
no ip igmp join-group group-address
Syntax Description
group-address
Address of the multicast group. This is a multicast IP address in four-part dotted-decimal notation.
Defaults
No multicast group memberships are predefined.
Command Modes
Interface configuration
Command History
Usage Guidelines
IP packets that are addressed to the group address are passed to the IP client process in the Cisco IOS software.
If all the multicast-capable routers and access servers that you administer are members of a multicast group, pinging that group causes all routers to respond, which can be a useful administrative and debugging tool.
Another reason to have a router join a multicast group is when other hosts on the network have an Interior Gateway Routing Protocol (IGRP) configuration that prevents them from correctly answering IGMP queries. Having the router join the multicast group causes upstream routers to maintain multicast routing table information for that group and keep the paths for that group active.
Examples
In the following example, the router joins multicast group 225.2.2.2:
ip igmp join-group 225.2.2.2Related Commands
ip igmp last-member-query-count
To configure the number of times that the router sends Internet Group Management Protocol (IGMP) group-specific or group-source-specific (with IGMP version 3) query messages in response to receiving a group-specific or group-source-specific leave message, use the ip igmp last-member-query-count command in interface configuration mode. To set this interval to the default value, use the no form of this command.
ip igmp last-member-query-count lmqc
no ip igmp last-member-query-count lmqc
Syntax Description
lmqc
Last member query count. The number of times, from 1 through 7, that the router sends group- or group-source-specific queries upon receipt of a message indicating a leave.
Defaults
LMQC is 2
Command Modes
Interface configuration
Command History
Usage Guidelines
When a router receives an IGMP version 2 (IGMPv2) or IGMP version 3 (IGMPv3) message indicating that a host wants to leave a group, source, or channel, it sends last-member-query-count group- or group-source-specific IGMP query messages at intervals of igmp-last-member-interval milliseconds. If no response is received after this period, the router stops forwarding for the group, source, or channel.
Caution
The leave latency in Cisco IOS software may increase by up to one last member query interval (LMQI) value when the router is processing more than one leave within a LMQI. In this case, the average leave latency is determined by the (LMQC + 0.5) * LMQI. The result is that the default leave latency can range from 2.0 to 3.0 seconds with an average of 2.5 seconds under a higher load of IGMP leave processing. The leave latency under load for the minimum LMQI value of 100 msec and a LMQC of 1 is from 100 to 200 milliseconds, with an average of 150 milliseconds. This is done to limit the impact of higher rates of IGMP leave messages.
If no response is received after this period, the router will stop forwarding traffic for that group, source, or channel only if no host replies to the query within the timeout period. The timeout period is determined by the ip igmp last-member-query-interval and the ip igmp last-member-query-count commands.
Examples
The following example changes the number of times that the router sends group-specific or group-source-specific query messages to 5:
interface tunnel 0ip igmp last-member-query-count 5:
Related Commands
ip igmp last-member-query-interval
To configure the interval at which the router sends Internet Group Management Protocol (IGMP) group-specific or group-source-specific (with IGMP Version 3) query messages, use the ip igmp last-member-query-interval command in interface configuration mode. To set this interval to the default value, use the no form of this command.
ip igmp last-member-query-interval interval
no ip igmp last-member-query-interval interval
Syntax Description
Defaults
interval: 1000 milliseconds (1 second)
Command Modes
Interface configuration
Command History
12.1
This command was introduced.
12.2(4)T
The highest interval integer value accepted was changed from 65,535 to 25,500.
Usage Guidelines
When a router receives an IGMP Version 2 (IGMPv2) or IGMP Version 3 (IGMPv3) message indicating that a host wants to leave a group, source, or channel, it sends last-member-query-count group, group-specific, or source-specific IGMP query messages at intervals set by the ip igmp last-member-query-interval command. If no response is received after this period, the router stops forwarding for the group, source, or channel.
The leave latency in Cisco IOS software may increase by up to one last member query interval (LMQI) value when the router is processing more than one leave within a LMQI. In this case, the average leave latency is determined by the (last member query count + 0.5) * LMQI. The result is that the default leave latency can range from 2.0 to 3.0 seconds with an average of 2.5 seconds under a higher load of IGMP leave processing. The leave latency under load for the minimum LMQI value of 100 msec and a last member query count of 1 is from 100 to 200 milliseconds, with an average of 150 milliseconds. This is done to limit the impact of higher rates of IGMP leave messages.
If no response is received after this period, the router will stop forwarding traffic for that group, source, or channel only if no host replies to the query within the timeout period. The timeout period is determined by the ip igmp last-member-query-interval and the ip igmp last-member-query-count commands.
Examples
The following example changes the IGMP group-specific host query message interval to 2000 milliseconds (2 seconds):
interface tunnel 0ip igmp last-member-query-interval 2000Related Commands
ip igmp limit (global)
To globally limit the number of Internet Group Management Protocol (IGMP) states resulting from IGMP, IGMP Version 3 lite (IGMP v3lite), and URL Rendezvous Directory (URD) membership states, use the ip igmp limit command in global configuration mode. To disable a configured IGMP state limit, use the no form of this command.
ip igmp limit number
no ip igmp limit number
Syntax Description
Defaults
This command is not configured by default. There is no default number of IGMP limits configured. You must configure the number of maximum IGMP states allowed globally on a router when you configure this command.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to configure a limit on the number of IGMP states resulting from IGMP, IGMP v3lite, and URD membership reports on a global basis. Membership reports sent after the configured limits have been exceeded are not entered in the IGMP cache and traffic for the excess membership reports is not forwarded.
Use the ip igmp limit (interface) command to configure the per-interface IGMP state limit.
Per-interface and per-system limits operate independently of each other and can enforce different configured limits. A membership state will be ignored if it exceeds either the per-interface limit or global limit.
Examples
The following example shows how to limit the number of IGMP states on a router to 300:
ip igmp limit 300Related Commands
ip igmp limit (interface)
To limit the number of Internet Group Management Protocol (IGMP) states resulting from IGMP, IGMP Version 3 lite (IGMP v3lite), and URL Rendezvous Directory (URD) membership states on a per-interface basis, use the ip igmp limit command in interface configuration mode. To disable a configured IGMP state limit, use the no form of this command.
ip igmp limit number [except access-list]
no ip igmp limit number [except access-list]
Syntax Description
Defaults
This command is not configured by default. There is no default number of IGMP limits configured. You must configure the number of maximum IGMP states allowed per interface on a router when you configure this command.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to configure a limit on the number of IGMP states resulting from IGMP, IGMP v3lite, and URD membership reports on a per-interface basis. Membership reports sent after the configured limits have been exceeded are not entered in the IGMP cache and traffic for the excess membership reports is not forwarded.
Use the ip igmp limit (global) command to configure the global IGMP state limit.
Per-interface and per-system limits operate independently of each other and can enforce different configured limits. A membership state will be ignored if it exceeds either the per-interface limit or global limit.
If you do not configure the except access-list keyword and argument, all IGMP states resulting from IGMP, IGMP v3lite, or URD are counted toward the configured cache limit on an interface. Use the except access-list keyword and argument to exclude particular groups or channels from counting toward the IGMP cache limit. An IGMP membership report is counted against the per-interface limit if it is permitted by the extended access list specified by the except access-list keyword and argument.
Examples
The following example shows how to limit the number of IGMP membership reports on Ethernet interface 0:
interface ethernet 0ip igmp limit 100The following example shows how to limit the number of IGMP membership reports on Ethernet interface 0. In this example, any IGMP membership reports from access list 0.0.0.1 do not count toward the configured state limit:
interface ethernet 0ip igmp limit 100 except 0.0.0.1Related Commands
ip igmp mroute-proxy
To enable Internet Group Management Protocol (IGMP) report forwarding of proxied (*, G) multicast static route (mroute) entries, use the ip igmp mroute-proxy command in interface configuration mode. To disable this service, use the no form of this command.
ip igmp mroute-proxy interface-type interface-number
no ip igmp mroute-proxy interface-type interface-number
Syntax Description
Defaults
The command is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
When used with the ip igmp proxy-service interface command, this command enables forwarding of IGMP reports to a proxy service interface for all (*, G) forwarding entries for this interface in the multicast forwarding table.
Examples
The following example shows how to configure the ip igmp mroute-proxy command on Ethernet interface 1 to request that IGMP reports be sent to loopback interface 0 for all groups in the mroute table that are forwarded to Ethernet interface 1. This example also shows how to configure the ip igmp proxy-service command on loopback interface 0 to enable the forwarding of IGMP reports out the interface for all groups on interfaces registered through the ip igmp mroute-proxy command.
interface loopback 0ip address 10.7.1.1 255.255.255.0ip pim dense-modeip igmp helper-address udl ethernet 0ip igmp proxy-service!interface ethernet 0ip address 10.2.1.1 255.255.255.0ip pim dense-modeip igmp unidirectional link!interface ethernet 1ip address 10.1.1.1 255.255.255.0ip pim sparse-modeip igmp mroute-proxy loopback 0Related Commands
ip igmp proxy-service
Enables the mroute proxy service.
ip igmp unidirectional-link
Configures an interface to be unidirectional and enables it for IGMP UDLR.
ip igmp proxy-service
To enable the mroute proxy service, use the ip igmp proxy-service command in interface configuration mode. To disable forwarding, use the no form of this command.
ip igmp proxy-service
no ip igmp proxy-service
Syntax Description
This command has no arguments or keywords.
Defaults
The command is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
Based on the Internet Group Management Protocol (IGMP) query interval, the router periodically checks the multicast static route (mroute) table for (*, G) forwarding entries that match interfaces configured with the ip igmp mroute-proxy command. Where there is a match, one IGMP report is created and received on this interface. The ip igmp proxy-service command is intended to be used with the ip igmp helper-address (UDL) command, in which case the IGMP report would be forwarded to an upstream router.
Examples
The following example shows how to configure the ip igmp mroute-proxy command on Ethernet interface 1 to request that IGMP reports be sent to loopback interface 0 for all groups in the mroute table that are forwarded to Ethernet interface 1. This example also shows how to configure the ip igmp proxy-service command on loopback interface 0 to enable the forwarding of IGMP reports out the interface for all groups on interfaces registered through the ip igmp mroute-proxy command.
interface loopback 0ip address 10.7.1.1 255.255.255.0ip pim dense-modeip igmp helper-address udl ethernet 0ip igmp proxy-service!interface ethernet 0ip address 10.2.1.1 255.255.255.0ip pim dense-modeip igmp unidirectional link!interface ethernet 1ip address 10.1.1.1 255.255.255.0ip pim sparse-modeip igmp mroute-proxy loopback 0Related Commands
ip igmp querier-timeout
To configure the timeout period before the router takes over as the querier for the interface after the previous querier has stopped querying, use the ip igmp querier-timeout command in interface configuration mode. To restore the default value, use the no form of this command.
ip igmp querier-timeout seconds
no ip igmp querier-timeout
Syntax Description
seconds
Number of seconds that the router waits after the previous querier has stopped querying and before it takes over as the querier. The range is from 30 to 300 seconds.
Command Default
The default timeout period is two times the query interval. The default query interval is 120 seconds.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
This command requires IGMP Version 2 (or higher).
By default, the router waits twice the query interval specified by the ip igmp query-interval command, after which, if it has heard no queries, it becomes the querier. By default, the ip igmp query-interval defaults to 60 seconds, which means the ip igmp querier-timeout defaults to 120 seconds.
Examples
The following example shows how to configure the router to wait 30 seconds from the time it received the last query before it takes over as the querier for the interface:
ip igmp querier-timeout 30Related Commands
ip igmp query-interval
Configures the frequency at which Cisco IOS software sends IGMP host query messages.
ip igmp query-interval
To configure the frequency at which Cisco IOS software sends Internet Group Management Protocol (IGMP) host query messages, use the ip igmp query-interval command in interface configuration mode. To return to the default frequency, use the no form of this command.
ip igmp query-interval seconds
no ip igmp query-interval
Syntax Description
seconds
Frequency, in seconds, at which to send IGMP host query messages. It can be a number from 0 to 65535. The default is 60 seconds.
Defaults
seconds: 60 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
Multicast routers send host membership query messages (host query messages) to discover which multicast groups have members on the attached networks of the router. Hosts respond with IGMP report messages indicating that they want to receive multicast packets for specific groups (that is, indicating that the host wants to become a member of the group). Host query messages are addressed to the all-hosts multicast group, which has the address 224.0.0.1, and has an IP time-to-live (TTL) value of 1.
The designated router for a LAN is the only router that sends IGMP host query messages:
•
•
If the router hears no queries for the timeout period (controlled by the ip igmp query-timeout command), it becomes the querier.
Caution
Examples
The following example changes the frequency at which the designated router sends IGMP host-query messages to 2 minutes:
interface tunnel 0ip igmp query-interval 120Related Commands
ip igmp query-max-response-time
To configure the maximum response time advertised in Internet Group Management Protocol (IGMP) queries, use the ip igmp query-max-response-time command in interface configuration mode. To restore the default value, use the no form of this command.
ip igmp query-max-response-time seconds
no ip igmp query-max-response-time
Syntax Description
seconds
Maximum response time, in seconds, advertised in IGMP queries. The default value is 10 seconds.
Defaults
seconds: 10 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is valid only when IGMP Version 2 is running.
This command controls the period during which the responder can respond to an IGMP query message before the router deletes the group.
Examples
The following example configures a maximum response time of 8 seconds:
ip igmp query-max-response-time 8Related Commands
ip igmp static-group
To configure the router to be a statically connected member of the specified group on the interface, or to statically forward for a multicast group onto the interface, use the ip igmp static-group command in interface configuration mode. To remove the router as a member of the group, use the no form of this command.
ip igmp static-group {* | group-address [source {source-address | ssm-map}]}
no ip igmp static-group {* | group-address [source {source-address | ssm-map}]}
Syntax Description
Defaults
A router is not a statically connected member of an IP multicast group.
Command Modes
Interface configuration
Command History
11.2
This command was introduced.
12.3(2)T
The source and the ssm-map keywords were added.
12.2(27)SBC
This command was integrated into Cisco IOS Release 12.2(27)SBC.
Usage Guidelines
When you configure the ip igmp static-group command, packets to the group are fast-switched out the interface, provided that packets were received on the correct reverse path forwarding (RPF) interface.
Configuring the ip igmp static-group command is unlike configuring the ip igmp join-group command, which allows the router to join the multicast group. This configuration of the ip igmp static-group command would cause the upstream routers to maintain the multicast routing table information for that group, which would ensure that all the paths to that multicast group are active.
If you configure the ip igmp join-group command for the same group address as the ip igmp static-group command, the ip igmp join-group command takes precedence, and the group behaves like a locally joined group.
The use of SSM mapping determines the source or sources associated with a specific source (S) and group (G) combination and puts the particular interface in the outging interface list (OIL) for that (S, G) entry. Traffic coming from source S destined toward group G will be forwarded out that interface regardless of a receiver joining the group on that interface.
Examples
The following example configures group address 192.168.2.2 on Ethernet interface 0:
interface ethernet 0ip igmp static-group 192.168.2.2The following example shows how to configure group address 192.168.2.3 to use SSM mapping for statically forwarded groups on Ethernet interface 0:
interface ethernet 0ip igmp static-group 192.168.2.3 source ssm-mapRelated Commands
ip igmp unidirectional-link
To configure an interface to be unidirectional and enable it for Internet Group Management Protocol (IGMP) unidirectional link routing (UDLR), use the ip igmp unidirectional-link command in interface configuration mode. To disable the unidirectional link (UDL), use the no form of this command.
ip igmp unidirectional-link
no ip igmp unidirectional-link
Syntax Description
This command has no arguments or keywords.
Defaults
No UDLR occurs.
Command Modes
Interface configuration
Command History
Usage Guidelines
One example of when you might configure this command is if you have traffic traveling via a satellite.
If you have a small number of receivers, another way to achieve UDLR is to configure a UDLR tunnel. See the descriptions of the tunnel udlr receive-only and tunnel udlr send-only commands.
Examples
The following example configures an upstream router with UDLR on serial interface 0:
ip multicast-routing!! Unidirectional link!interface serial 0description Unidirectional to downlink-rtrip address 10.0.0.1 255.0.0.0ip pim sparse-dense-modeip igmp unidirectional-linkno keepaliveRelated Commands
ip igmp v3lite
To enable acceptance and processing of Internet Group Management Protocol Version 3 lite (IGMP v3lite) membership reports on an interface, use the ip igmp v3lite command in interface configuration mode. To disable IGMP v3lite, use the no form of this command.
ip igmp v3lite
no ip igmp v3lite
Syntax Description
This command has no arguments or keywords.
Defaults
IGMPv3 lite membership reports are not accepted and processed.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must define a Source Specific Multicast (SSM) range of IP addresses using the ip pim ssm global configuration command. When IGMP v3lite is enabled, it is supported in the SSM range of addresses only.
Examples
The following example shows how to configure IGMP v3lite on Ethernet interface 3/1:
interface ethernet 3/1ip igmp v3liteRelated Commands
ip igmp version
To configure which version of Internet Group Management Protocol (IGMP) the router uses, use the ip igmp version command in interface configuration mode. To restore the default value, use the no form of this command.
ip igmp version {1 | 2 | 3}
no ip igmp version
Syntax Description
Defaults
Version 2
Command Modes
Interface configuration
Command History
Usage Guidelines
All routers on the subnet must support the same version. The router does not automatically detect Version 1 routers and switch to Version 1 as did earlier releases of the Cisco IOS software. Hosts can have any IGMP version (1, 2, or 3) and the router will correctly detect their presence and query them appropriately.
Some commands require IGMP Version 2 or 3, such as the ip igmp query-max-response-time and ip igmp query-timeout commands.
Examples
The following example configures the router to use IGMP Version 3:
ip igmp version 3Related Commands
ip mrm
To configure an interface to operate as a Test Sender or Test Receiver, or both, for Multicast Routing Monitor (MRM), use the ip mrm command in interface configuration mode. To remove the interface as a Test Sender or Test Receiver, use the no form of this command.
ip mrm {test-sender | test-receiver | test-sender-receiver}
no ip mrm
Syntax Description
Command Default
No interface is configured to operate as a Test Sender or a Test Receiver, or both, for MRM.
Command Modes
Interface configuration
Command History
Usage Guidelines
The Test Sender and Test Receiver can be either a router or a host.
If a router (or host) belongs to more than one test group, it can be a Test Sender for one group and a Test Receiver for the other group. It, however, cannot be the Test Sender and Test Receiver for the same group.
Examples
The following example shows how to configure an interface to operate as a Test Sender. In this example, Ethernet interface 0 is configured to operate as a Test Sender.
interface ethernet 0 ip mrm test-senderRelated Commands
receivers
Establishes Test Receivers for MRM.
senders
Establishes Test Senders for MRM.
ip mrm accept-manager
To configure a Test Sender or Test Receiver to accept requests only from Managers that pass an access list, use the ip mrm accept-manager command in global configuration mode. To remove the restriction, use the no form of this command.
ip mrm accept-manager access-list [test-sender | test-receiver]
no ip mrm accept-manager access-list
Syntax Description
Command Default
Test Senders and Test Receivers respond to all Managers.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to control which Managers a Test Sender or Test Receiver must respond to.
If neither the test-sender nor test-receiver keyword is configured, the access list applies to both.
Examples
The following example shows how to configure a Test Sender to respond only to Managers that pass an access list. In this example, the Test Sender is configured to respond only to the Managers that passed the ACL named supervisor.
ip mrm accept-manager supervisor!ip access-list standard supervisorremark Permit only the Manager from the Central Officepermit 172.18.2.4!Related Commands
ip mrm
Configures an interface to operate as a Test Sender or Test Receiver, or both, for MRM.
ip mrm manager
To specify the Multicast Routing Monitor (MRM) test to be created or modified and enter MRM manager configuration mode, use the ip mrm manager command in global configuration mode. To remove the test, use the no form of this command.
ip mrm manager test-name
no ip mrm manager test-name
Syntax Description
Command Default
No MRM tests are configured.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip mrm manager command to specify the name of the MRM test to be created or modified and enter MRM manager configuration mode where you specify the parameters of the MRM test.
Examples
The following example shows how to enter MRM manager configuration mode for the MRM test named test1:
Router(config)# ip mrm manager test1Router(config-mrm-manager)#Related Commands
mrm
Starts or stops an MRM test.
show ip mrm manager
Displays test information for MRM.
ip mroute
To configure a multicast static route (mroute), use the ip mroute command in global configuration mode. To remove the route, use the no form of this command.
ip mroute [vrf vrf-name] source-address mask [protocol as-number] {rpf-address | interface-type interface-number} [distance]
no ip mroute [vrf vrf-name] source mask [protocol as-number] {rpf-address | interface-type interface-number} [distance]
Syntax Description
Defaults
distance: 0
Command Modes
Global configuration
Command History
11.0
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
This command allows you to statically configure where multicast sources are located (even though the unicast routing table shows something different).
When a source range is specified, the rpf-address argument applies only to those sources.
Examples
The following example configures all sources via a single interface (in this case, a tunnel):
ip mroute 0.0.0.0 0.0.0.0 tunnel0The following example configures all specific sources within a network number to be reachable through 172.30.10.13:
ip mroute 172.16.0.0 255.255.0.0 172.30.10.13The following example causes this multicast static route to take effect if the unicast routes for any given destination go away:
ip mroute 0.0.0.0 0.0.0.0 serial0 200ip mroute-cache
To configure IP multicast fast switching or multicast distributed switching (MDS), use the ip mroute-cache command in interface configuration mode. To disable either of these features, use the no form of this command.
ip mroute-cache [distributed]
no ip mroute-cache [distributed]
Syntax Description
Defaults
On the Cisco 7500 series, IP multicast fast switching is enabled; MDS is disabled.
On the Cisco 12000 series, MDS is disabled.Command Modes
Interface configuration
Command History
10.0
This command was introduced.
11.2(11)GS
The distributed keyword was added.
Usage Guidelines
On the Cisco 7500 Series
If multicast fast switching is disabled on an incoming interface for a multicast routing table entry, the packet will be sent at process level for all interfaces in the outgoing interface list.
If multicast 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 multicast fast switching is enabled (like unicast routing), debug messages are not logged. If you want to log debug messages, disable fast switching.
If MDS is not enabled on an incoming interface that is capable of MDS, incoming multicast packets will not be distributed switched; they will be fast switched at the Route Processor (RP). Also, if the incoming interface is not capable of MDS, packets will get fast switched or process-switched at the RP.
If MDS is enabled on the incoming interface, but at least one of the outgoing interfaces cannot fast switch, packets will be process switched. We recommend that you disable fast switching on any interface when MDS is enabled.
On the Cisco 12000 Series
On the GSR, all interfaces should be configured for MDS because that is the only switching mode.
Examples
The following example enables IP multicast fast switching on the interface:
ip mroute-cacheThe following example disables IP multicast fast switching on the interface:
no ip mroute-cacheThe following example enables MDS on the interface:
ip mroute-cache distributedThe following example disables MDS and IP multicast fast switching on the interface:
no ip mroute-cache distributedip msdp border
To configure a router that borders a Protocol Independent Multicast (PIM) sparse mode region and dense mode region to use Multicast Source Discovery Protocol (MSDP), use the ip msdp border command in global configuration mode. To prevent this action, use the no form of this command.
ip msdp [vrf vrf-name] border sa-address interface-type interface-number
no ip msdp [vrf vrf-name] border sa-address interface-type interface-number
Syntax Description
Defaults
The active sources in the dense mode region will not participate in MSDP.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
Use this command if you want the router to send SA messages for sources active in the PIM dense mode region to MSDP peers.
Note
Note
Note
Examples
In the following example, the local router is not an RP. It borders a PIM sparse mode region with a dense mode region. It uses the IP address of Ethernet interface 0 as the "RP" address in SA messages.
ip msdp border sa-address ethernet0Related Commands
ip msdp cache-rejected-sa
To cache Source-Active (SA) request messages rejected from Multicast Source Discovery Protocol (MSDP) peers, use the ip msdp cache-rejected-sa command in global configuration mode. To stop tracking SA request messages, use the no form of this command.
ip msdp cache-rejected-sa number-of-entries
no ip msdp cache-rejected-sa number-of-entries
Syntax Description
Defaults
Rejected SA request messages are not stored.
Command Modes
Global configuration
Command History
12.0(22)S
This command was introduced.
12.1E
This command was integrated into Cisco IOS Release 12.1E.
12.2
This command was integrated into Cisco IOS Release 12.2.
Usage Guidelines
Use the ip msdp cache-rejected-sa command to configure the router to store SA messages that have been recently received from an MSDP peer but were rejected. Once this command is enabled, the router will maintain a rejected SA cache that stores the most recent rejected SA messages. The number of rejected SA message entries to be stored in the rejected SA cache is configured with the number-of-entries argument. If the rejected SA cache overflows, entries are overwritten, starting from the first entry.
Note
Use the show ip msdp sa-cache command with the rejected-sa keyword to display SA messages rejected from MSDP peers.
Examples
The following example shows how to enable the router to store a maximum of 200 messages rejected from MSDP peers:
Router(config)# ip msdp cache-rejected-sa 200Related Commands
ip msdp cache-sa-state
To have the router create Source-Active (SA) state, use the ip msdp cache-sa-state command in global configuration mode.
ip msdp cache-sa-state [vrf vrf-name]
Syntax Description
vrf
(Optional) Supports the multicast VPN routing and forwarding (VRF) instance.
vrf-name
(Optional) Name assigned to the VRF.
Defaults
The router creates SA state for all Multicast Source Discovery Protocol (MSDP) SA messages it receives.
Command Modes
Global configuration
Command History
Usage Guidelines
This command is automatically configured if at least one MSDP peer is configured. It cannot be disabled.
If you are running a version of Cisco IOS software prior to Release 12.1(7), we recommend enabling the ip msdp cache-sa-state command.
Examples
The following example shows how the ip msdp cache-sa-state command is enabled when an MSDP peer is configured:
...ip classlessip msdp peer 192.168.1.2 connect-source Loopback0ip msdp peer 192.169.1.7ip msdp mesh-group outside-test 192.168.1.2ip msdp cache-sa-stateip msdp originator-id Loopback0...Related Commands
ip msdp default-peer
To define a default peer from which to accept all Multicast Source Discovery Protocol (MSDP) Source-Active (SA) messages, use the ip msdp default-peer command in global configuration mode. To remove the default peer, use the no form of this command.
ip msdp [vrf vrf-name] default-peer {peer-address | peer-name} [prefix-list list]
no ip msdp [vrf vrf-name] default-peer
Syntax Description
Defaults
No default MSDP peer exists.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
Use the ip msdp default-peer command if you do not want to configure your MSDP peer to be a BGP peer also.
If only one MSDP peer is configured (with the ip msdp peer command), it will be used as a default peer. Therefore, you need not configure a default peer with this command.
If the prefix-list list keyword and argument are not specified, all SA messages received from the configured default peer are accepted.
Remember to configure a BGP prefix list if you intend to configure the prefix-list list keyword and argument with the ip msdp default-peer command.
If the prefix-list list keyword and argument are specified, SA messages originated from rendezvous points (RPs) specified by the prefix-list list keyword and argument will be accepted from the configured default peer. If the prefix-list list keyword and argument are specified but no prefix list is configured, the default peer will be used for all prefixes.
You can enter multiple ip msdp default-peer commands, with or without the prefix-list keyword, as follows. However, all commands must either have the keyword or all must not have the keyword.
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Examples
The following example configures the router at IP address 192.168.1.3 as the default peer to the local router:
ip msdp peer 192.168.1.3ip msdp peer 192.168.3.5ip msdp default-peer 192.168.1.3The following example configures two default peers:
ip msdp peer 172.18.2.3ip msdp peer 172.19.3.5ip msdp default-peer 172.18.2.3 prefix-list site-cip prefix-list site-a permit 172.18.0.0/16ip msdp default-peer 172.19.3.5 prefix-list site-aip prefix-list site-c permit 172.19.0.0/16Related Commands
ip msdp description
To add descriptive text to the configuration for a Multicast Source Discovery Protocol (MSDP) peer, use the ip msdp description command in global configuration mode. To remove the description, use the no form of this command.
ip msdp [vrf vrf-name] description {peer-name | peer-address} text
no ip msdp [vrf vrf-name] description {peer-name | peer-address}
Syntax Description
Defaults
No description is associated with an MSDP peer.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
Configure a description to make the MSDP peer easier to identify. This description is displayed in the output of the show ip msdp peer command.
Examples
The following example configures the router at the IP address 172.17.1.2 with a description indicating it is a router at customer A:
ip msdp description 172.17.1.2 router at customer aRelated Commands
ip msdp filter-sa-request
To configure the router to send Source-Active (SA) request messages to the Multicast Source Discovery Protocol (MSDP) peer when a new joiner from a group becomes active, use the ip msdp filter-sa-request command in global configuration mode. To prevent this action, use the no form of this command.
ip msdp [vrf vrf-name] filter-sa-request {peer-address | peer-name} [list access-list]
no ip msdp [vrf vrf-name] filter-sa-request {peer-address | peer-name}
Syntax Description
Defaults
If this command is not configured, all SA request messages are honored. If this command is configured but no access list is specified, all SA request messages are ignored.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
By default, the router honors all SA request messages from peers. Use this command if you want to control exactly which SA request messages the router will honor.
If no access list is specified, all SA request messages are ignored. If an access list is specified, only SA request messages from those groups permitted will be honored, and all others will be ignored.
Examples
The following example configures the router to filter SA request messages from the MSDP peer at 172.16.2.2. SA request messages from sources on the network 192.168.22.0 pass access list 1 and will be honored; all others will be ignored.
ip msdp filter sa-request 172.16.2.2 list 1access-list 1 permit 192.4.22.0 0.0.0.255Related Commands
ip msdp keepalive
To adjust the interval at which a Multicast Source Discovery Protocol (MSDP) peer will send keepalive messages and the interval at which the MSDP peer will wait for keepalive messages from other peers before declaring them down, use the ip msdp keepalive command in global configuration mode. To restore the default values, use the no form of this command.
ip msdp [vrf vrf-name] keepalive {peer-address | peer-name} keepalive-interval hold-time-interval
no ip msdp [vrf vrf-name] keepalive {peer-address | peer-name}
Syntax Description
Command Default
An MSDP peer sends keepalives messages at an interval of once every 60 seconds. The hold-time interval for an MSDP peer is set to 75 seconds.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip msdp keepalive command to adjust the interval at which an MSDP peer will send keepalive messages and the interval at which the MSDP peer will wait for keepalive messages from other peers before declaring them down.
Once an MSDP peering session is established, each side of the connection sends a keepalive message and sets a keepalive timer. If the keepalive timer expires, the local MSDP peer sends a keepalive message and restarts its keepalive timer; this interval is referred to as the keepalive interval. Use the keepalive-interval argument to adjust the interval for which keepalive messages will be sent. The keepalive timer is set to the value specified for the keepalive-interval argument when the peer comes up. The keepalive timer is reset to the value of the keepalive-interval argument whenever an MSDP keepalive message is sent to the peer and reset when the timer expires. The keepalive timer is deleted when an MSDP peering session is closed. By default, the keepalive timer is set to 60 seconds.
Note
The hold-time timer is initialized to the value of the hold-time-interval argument whenever an MSDP peering connection is established, and is reset to value of the hold-time-interval argument whenever an MSDP keepalive message is received. The hold-time timer is deleted whenever an MSDP peering connection is closed. By default, the hold-time interval is set to 75 seconds.
Use the hold-time-interval keyword to adjust the interval at which the MSDP peer will wait for keepalive messages from other peers before declaring them down. By default, it may take as long as 75 seconds for an MSDP peer to detect that a peering session with another MSDP peer has gone down. In network environments with redundant MSDP peers, decreasing the hold-time interval (by lowering the value for hold-time-interval argument from the default of 75 seconds) can expedite the reconvergence time of MSDP peers in the event that an MSDP peer fails.
Note
Examples
The following example shows how to set the keepalive interval to 40 seconds and the hold-time interval to 55 seconds for the MSDP peer at 172.16.100.10:
ip msdp keepalive 172.16.100.10 40 55Related Commands
ip msdp mesh-group
To configure a Multicast Source Discovery Protocol (MSDP) peer to be a member of a mesh group, use the ip msdp mesh-group command in global configuration mode. To remove an MSDP peer from a mesh group, use the no form of this command.
ip msdp [vrf vrf-name] mesh-group mesh-name {peer-address | peer-name}
no ip msdp [vrf vrf-name] mesh-group mesh-name {peer-address | peer-name}
Syntax Description
Defaults
The MSDP peers do not belong to a mesh group.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
A mesh group is a group of MSDP speakers that have fully meshed MSDP connectivity among themselves. Source-Active (SA) messages received from a peer in a mesh group are not forwarded to other peers in the same mesh group.
Mesh groups can be used to achieve two goals:
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Examples
The following example configures the MSDP peer at address 192.168.1.3 to be a member of the mesh group named internal:
ip msdp mesh-group internal 192.168.1.3ip msdp originator-id
To allow a Multicast Source Discovery Protocol (MSDP) speaker that originates a Source-Active (SA) message to use the IP address of the interface as the rendezvous point (RP) address in the SA message, use the ip msdp originator-id command in global configuration mode. To prevent the RP address from being derived in this way, use the no form of this command.
ip msdp [vrf vrf-name] originator-id interface-type interface-number
no ip msdp [vrf vrf-name] originator-id interface-type interface-number
Syntax Description
Defaults
The RP address is used as the originator ID.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
The ip msdp originator-id command identifies an interface type and number to be used as the RP address in an SA message.
Use this command if you want to configure a logical RP. Because only RPs and MSDP border routers originate SAs, there are times when it is necessary to change the ID used for this purpose.
If both the ip msdp border sa-address and ip msdp originator-id commands are configured the address derived from the ip msdp originator-id command determines the address of the RP to be used in the SA message.
Examples
The following example configures the IP address of Ethernet interface 1 as the RP address in SA messages:
ip msdp originator-id ethernet1Related Commands
ip msdp border
Configures a router that borders a PIM sparse mode region and dense mode region to use MSDP.
ip msdp peer
To configure a Multicast Source Discovery Protocol (MSDP) peer, use the ip msdp peer command in global configuration mode. To remove the peer relationship, use the no form of this command.
ip msdp [vrf vrf-name] peer {peer-name | peer-address} [connect-source interface-type interface-number] [remote-as as-number]
no ip msdp [vrf vrf-name] peer {peer-name | peer-address}
Syntax Description
Defaults
No MSDP peer is configured.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
The router specified should also be configured as a BGP neighbor.
If you are also BGP peering with this MSDP peer, you should use the same IP address for MSDP as you do for BGP. However, you are not required to run BGP or multiprotocol BGP with the MSDP peer, as long as there is a BGP or MBGP path between the MSDP peers. If there is no path, you must configure the ip msdp default-peer command.
Examples
The following example configures the router at the IP address 192.168.1.2 as an MSDP peer to the local router. The neighbor belongs to autonomous system 109.
ip msdp peer 192.168.1.2 connect-source ethernet 0/0router bgp 110network 192.168.0.0neighbor 192.168.1.2 remote-as 109neighbor 192.168.1.2 update-source ethernet 0/0The following example configures the router at the IP address 192.168.1.3 as an MSDP peer to the local router:
ip msdp peer 192.168.1.3The following example configures the router at the IP address 192.168.1.4 to be an MSDP peer in autonomous system 109. The primary address of Ethernet interface 0/0 is used as the source address for the TCP connection.
ip msdp peer 192.168.1.4 connect-source ethernet 0/0 remote-as 109Related Commands
ip msdp default-peer
Defines a default peer from which to accept all MSDP SA messages.
neighbor remote-as
Adds an entry to the BGP neighbor table.
ip msdp redistribute
To configure which (S, G) entries from the multicast routing table are advertised in Source-Active (SA) messages originated to Multicast Source Discovery Protocol (MSDP) peers, use the ip msdp redistribute command in global configuration mode. To remove the filter, use the no form of this command.
ip msdp [vrf vrf-name] redistribute [list access-list-name] [asn as-access-list-number] [route-map map-name]
no ip msdp [vrf vrf-name] redistribute
Syntax Description
Defaults
If no portion of this command is configured, only local sources are advertised, provided they send to groups for which the router is a rendezvous point (RP).
If no portion of this command is configured and if the ip msdp border sa-address command is configured, all local sources are advertised.
If the ip msdp redistribute command is configured with no keywords, no multicast sources are advertised.Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
This command affects SA message origination, not SA message forwarding. If you want to filter which SA messages are forwarded to MSDP peers, use the ip msdp sa-filter in or ip msdp sa-filter out command.
The ip msdp redistribute command controls which (S, G) pairs the router advertises from the multicast routing table. By default, only sources within the local domain are advertised. Use the following guidelines for the ip msdp redistribute command:
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Examples
The following example configures which (S, G) entries from the multicast routing table are advertised in SA messages originated to MSDP peers:
ip msdp redistribute route-map customer-sourcesroute-map customer-sources permitmatch as-path customer-asip as-path access-list ^109$Related Commands
ip msdp sa-filter in
To configure an incoming filter list for Source-Active (SA) messages received from the specified Multicast Source Discovery Protocol (MSDP) peer, use the ip msdp sa-filter in command in global configuration mode. To remove the filter, use the no form of this command.
ip msdp [vrf vrf-name] sa-filter in {peer-address | peer-name} [list access-list-name] [route-map map-name]
no ip msdp [vrf vrf-name] sa-filter in {peer-address | peer-name} [list access-list-name] [route-map map-name]
Syntax Description
Defaults
If this command is not configured, no incoming messages are filtered; all SA messages are accepted from the peer.
If the command is configured, but no access list or route map is specified, all source/group pairs from the peer are filtered.
If both the list and route-map keywords are used, all conditions specified by these keywords must be true to pass any (S, G) pair in incoming SA messages.Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Examples
The following example configures the router to filter all SA messages from the peer at 192.168.1.3:
ip msdp peer 192.168.1.3 connect-source Ethernet0/0ip msdp sa-filter in 192.168.1.3Related Commands
ip msdp peer
Configures an MSDP peer.
ip msdp sa-filter out
Configures an outgoing filter list for SA messages sent to the specified MSDP peer.
ip msdp sa-filter out
To configure an outgoing filter list for Source-Active (SA) messages sent to the specified Multicast Source Discovery Protocol (MSDP) peer, use the ip msdp sa-filter out command in global configuration mode. To remove the filter, use the no form of this command.
ip msdp [vrf vrf-name] sa-filter out {peer-address | peer-name} [list access-list-name] [route-map map-name]
no ip msdp [vrf vrf-name] sa-filter out {peer-address | peer-name} [list access-list-name] [route-map map-name]
Syntax Description
Defaults
If this command is not configured, no outgoing messages are filtered; all SA messages received are forwarded to the peer.
If the command is configured, but no access list or route map is specified, all source/group pairs are filtered.
If both the list and route-map keywords are used, all conditions specified by these keywords must be true to pass any (S, G) pairs in outgoing SA messages.Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Examples
The following example allows only (S, G) pairs that pass access list 100 to be forwarded in an SA message to the peer at the IP address 192.168.1.5:
ip msdp peer 192.168.1.5 connect-source ethernet 0/0ip msdp sa-filter out 192.168.1.5 list 100access-list 100 permit ip 172.1.0.0 0.0.255.255 224.2.0.0 0.0.255.255Related Commands
ip msdp peer
Configures an MSDP peer.
ip msdp sa-filter in
Configures an incoming filter list for SA messages received from the specified MSDP peer.
ip msdp sa-limit
To limit the number of Source-Active (SA) messages from a Multicast Source Discovery Protocol (MSDP) peer that the router will allow in the SA cache, use the ip msdp sa-limit command in global configuration mode. To remove this limit, use the no form of this command.
ip msdp sa-limit {peer-name | peer-address} sa-limit
no ip msdp sa-limit {peer-name | peer-address} sa-limit
Syntax Description
peer-name | peer-address
Domain Name System (DNS) name or IP address of the router that is to be the MSDP peer.
sa-limit
Maximum number of SA messages from an MSDP peer allowed in the SA cache.
Defaults
By default, no SA message limit is set.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to prevent distributed denial of service attacks. We recommend configuring this command on all MSDP peer connections.
The output of the show ip msdp count, show ip msdp peer, and show ip msdp summary commands will display the number of SA messages from each MSDP peer that is in the SA cache. If the ip msdp sa-limit command is configured, the output of the show ip msdp peer command will also display the value of the SA message limit for each MSDP peer.
Examples
The following example configures the SA message limit to 100 for the MSDP peer with IP address 172.16.0.0:
ip msdp sa-limit 172.16.0.0 100Related Commands
ip msdp sa-request
Note
To configure the router to send Source-Active (SA) request messages to the Multicast Source Discovery Protocol (MSDP) peer when a new joiner from the group becomes active, use the ip msdp sa-request command in global configuration mode. To prevent this action, use the no form of this command.
ip msdp [vrf vrf-name] sa-request {peer-address | peer-name}
no ip msdp [vrf vrf-name] sa-request {peer-address | peer-name}
Syntax Description
Defaults
The router does not send SA request messages to the MSDP peer.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
By default, the router does not send any SA request messages to its MSDP peers when a new member joins a group and wants to receive multicast traffic. The new member waits to receive any SA messages that eventually arrive.
Use this command if you want a new member of a group to learn the current, active multicast sources in a connected Protocol Independent Multicast sparse mode (PIM-SM) domain that are sending to a group. The router will send SA request messages to the specified MSDP peer when a new member joins a group. The peer replies with the information in its SA cache. If the peer does not have a cache configured, this command provides nothing.
An alternative to this command is using the ip msdp cache-sa-state command to have the router cache messages.
Examples
The following example configures the router to send SA request messages to the MSDP peer at the IP address 192.168.10.1:
ip msdp sa-request 192.168.10.1Related Commands
ip msdp cache-sa-state
Enables the router to create SA state.
ip msdp peer
Configures an MSDP peer.
ip msdp shutdown
To administratively shut down a configured Multicast Source Discovery Protocol (MSDP) peer, use the ip msdp shutdown command in global configuration mode. To bring the peer back up, use the no form of this command.
ip msdp [vrf vrf-name] shutdown {peer-address | peer-name}
no ip msdp [vrf vrf-name] shutdown {peer-address | peer-name}
Syntax Description
Defaults
No action is taken to shut down an MSDP peer.
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Examples
The following example shuts down the MSDP peer at IP address 192.168.7.20:
ip msdp shutdown 192.168.7.20Related Commands
ip msdp timer
To adjust the interval at which Multicast Source Discovery Protocol (MSDP) peers will wait after peering sessions are reset before attempting to reestablish the peering sessions, use the ip msdp timer command in global configuration mode. To restore the default value, use the no form of this command.
ip msdp [vrf vrf-name] timer connection-retry-interval
no ip msdp [vrf vrf-name] timer
Syntax Description
Command Default
An MSDP peer will wait 30 seconds after a peering session is reset before attempting to reestablish the peering session with any peer.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip msdp timer command to adjust the interval at which all MSDP peers will wait after peering sessions are reset before attempting to reestablish the peering sessions. This interval is referred to as the connection-retry interval. By default, MSDP peers will wait 30 seconds after is session is reset before attempting to reestablish sessions with other peers. When the ip msdp timer command is configured, the configured connection-retry interval applies to all MSDP peering sessions on the router.
In network environments where fast recovery of Source-Active (SA) messages is required (such as in trading floor network environments), you may want to decrease the connection-retry interval to a time value less than the default value of 30 seconds.
Examples
The following example shows how to set the connection-retry interval for all MSDP peers to 20 seconds:
ip msdp timer 20Related Commands
ip msdp ttl-threshold
To limit which multicast data packets are sent in Source-Active (SA) messages to a Multicast Source Discovery Protocol (MSDP) peer, use the ip msdp ttl-threshold command in global configuration mode. To restore the default value, use the no form of this command.
ip msdp [vrf vrf-name] ttl-threshold {peer-address | peer-name} ttl-value
no ip msdp [vrf vrf-name] ttl-threshold {peer-address | peer-name}
Syntax Description
Defaults
ttl-value: 0
Command Modes
Global configuration
Command History
12.0(7)T
This command was introduced.
12.0(23)S
The vrf keyword and vrf-name argument were added.
12.2(13)T
The vrf keyword and vrf-name argument were added.
Usage Guidelines
This command limits which multicast data packets are sent in data-encapsulated SA messages. Only multicast packets with an IP header TTL greater than or equal to the ttl-value argument are sent to the MSDP peer specified by the IP address or name.
Use this command if you want to use TTL to scope your multicast data traffic. For example, you could limit internal traffic to a TTL of 8. If you want other groups to go to external locations, you would need to send those packets with a TTL greater than 8.
Examples
The following example configures a TTL threshold of 8 hops:
ip msdp ttl-threshold 192.168.1.5 8Related Commands
ip multicast boundary
To configure an administratively scoped boundary, use the ip multicast boundary command in interface configuration mode. To remove the boundary, use the no form of this command.
ip multicast boundary access-list [filter-autorp]
no ip multicast boundary [filter-autorp]
Syntax Description
Defaults
There is no boundary.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to configure an administratively scoped boundary on an interface to filter multicast group addresses in the range defined by the access-list argument. A standard access list defines the range of addresses affected. When this command is configured, no multicast data packets are allowed to flow across the boundary from either direction. Restricting multicast data packet flow enables reuse of the same multicast group address in different administrative domains.
If you configure the filter-autorp keyword, the administratively scoped boundary also examines Auto-RP discovery and announcement messages and removes any Auto-RP group range announcements from the Auto-RP packets that are denied by the boundary ACL. An Auto-RP group range announcement is permitted and passed by the boundary only if all addresses in the Auto-RP group range are permitted by the boundary ACL. If any address is not permitted, the entire group range is filtered and removed from the Auto-RP message before the Auto-RP message is forwarded.
Examples
The following example sets up a boundary for all administratively scoped addresses:
access-list 1 deny 239.0.0.0 0.255.255.255access-list 1 permit 224.0.0.0 15.255.255.255interface ethernet 0ip multicast boundary 1Related Commands
ip multicast cache-headers
To allocate a circular buffer to store IP multicast packet headers that the router receives, use the ip multicast cache-headers command in global configuration mode. To remove the buffer, use the no form of this command.
ip multicast [vrf vrf-name] cache-headers [rtp]
no ip multicast [vrf vrf-name] cache-headers [rtp]
Syntax Description
Defaults
The command is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
You can store IP multicast packet headers in a cache and then display them to determine the following information:
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Note
Use the show ip mpacket command to display the buffer.
Examples
The following example allocates a buffer to store IP multicast packet headers:
ip multicast cache-headers
Related Commands
ip multicast default-rpf-distance
When configuring Internet Group Management Protocol (IGMP) unidirectional link routing (UDLR), to change the distance given to the default Reverse Path Forwarding (RPF) interface, use the ip multicast default-rpf-distance command in global configuration mode. To restore the default value, use the no form of this command.
ip multicast default-rpf-distance distance
no ip multicast default-rpf-distance distance
Syntax Descriptionno ip multicast default-rpf-distance
Defaults
distance: 15
Command Modes
Global configuration
Command History
Usage Guidelines
This command is optional. If you want to receive all multicast traffic from all sources on the unidirectional link (UDL), as long as 15 is the lowest distance, you need not change the value of 15.
The default RPF interface is selected when an IGMP query message is received on a UDL and indicates to the router that all sources will use RPF to reach the UDL interface.
Any explicit sources learned by routing protocols will take preference as long as their distance is less than the distance argument configured with the ip multicast default-rpf-distance command.
You might consider changing the default value for one of the following reasons:
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Examples
The following example configures a distance of 20:
ip multicast default-rpf-distance 20Related Commands
ip igmp unidirectional-link
Configures an interface to be unidirectional and enables it for IGMP UDLR.
ip multicast heartbeat
To monitor the health of multicast delivery and be alerted when the delivery fails to meet certain parameters, use the ip multicast heartbeat command in global configuration mode. To disable the heartbeat, use the no form of this command.
ip multicast heartbeat group-address minimum-number window-size interval
no ip multicast heartbeat group-address minimum-number window-size interval
Syntax Description
Defaults
This command is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
The subject group is joined at the subject interface so that multicast data for the subject group will be attracted toward the subject router.
The router monitors multicast packets destined to the group address at the interval value. This is a binary decision. That is, the number of packets seen in this period is not as important as whether any packet for the group is seen.
If multicast packets were observed in less than the minimum-number value out of the last window-size value intervals, a Simple Network Management Protocol (SNMP) trap would be sent from this router to a network management station to indicate a loss of heartbeat exception. This trap will be defined in CISCO-IPMROUTE-MIB.my.
The interval value must be a multiple of 10. In multicast distributed switching (MDS), statistics from the Versatile Interface Processor (in the Route Switch Processor) or the Label Controller (in the Cisco 12000 series) are passed to the routing processor once every 10 seconds. Monitoring packets not in intervals of multiple of 10 seconds may lead to incorrect decisions.
This command does not create any multicast routing entries that are necessary for the monitoring of the heartbeat packets. These entries can be created by either the downstream members of the group, or with the ip pim join-group or ip pim static-group command. If a multicast routing entry corresponding to a group address expires due to lack of interest from the downstream members, the monitoring for the subject group would not work; that is, no more SNMP traps would be sent.
Examples
The following is an example configuration of the ip multicast heartbeat command:
snmp-server enable traps ipmulticast-heartbeatip multicast heartbeat 224.0.1.53 1 1 10In this example, multicast packets forwarded through this router to group address 224.0.1.53 will be monitored. If no packet for this group is received in a 10-second interval, an SNMP trap will be sent to a designated SNMP management station.
Note
Related Commands
debug ip mhbeat
Monitors the action of the heartbeat trap.
snmp-server enable traps
Enables the router to send SNMP traps.
ip multicast helper-map
To allow IP multicast routing in a multicast-capable internetwork between two broadcast-only internetworks, use the ip multicast helper-map command in interface configuration mode. To disable this function, use the no form of this command.
ip multicast helper-map {group-address broadcast-address | broadcast multicast-address} access-list [ttl remapping-value]
no ip multicast helper-map {group-address broadcast-address | broadcast multicast-address} access-list [ttl remapping-value]
Syntax Description
Command Default
No conversion between broadcast and multicast occurs.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
When a multicast-capable internetwork is between two broadcast-only internetworks, you can convert broadcast traffic to multicast at the first hop router, and convert it back to broadcast at the last hop router before delivering the packets to the broadcast clients. However, broadcast packets with the IP source address of 0.0.0.0 (such as a Dynamic Host Configuration Protocol [DHCP] request) will not be translated to any multicast group. Thus, you can take advantage of the multicast capability of the intermediate multicast internetwork. This feature prevents unnecessary replication at the intermediate routers and allows multicast fast switching in the multicast internetwork.
If you need to send a directed broadcast to the subnet, the outgoing interface of the last hop router can be configured with an IP broadcast address of x.x.x.255, where x.x.x.0 is the subnet that you are trying to reach; otherwise, the packet will be converted to 255.255.255.255.
By default, many broadcast applications use a default TTL value of 1. Because the helper-map applies the decremented TTL value of the incoming broadcast packet for the generated multicast packet, and most broadcast applications use a TTL value of 1 hop, broadcast packets may not be translated to multicast packets, and thus, may be dropped rather than forwarded. To circumvent this potential issue, you can manually configure the TTL value for broadcast packets being translated into multicast packets using the ttl keyword and remapping-value argument. For the remapping-value argument, specify a value that will enable the translated packets to reach multicast receivers.
Examples
The following example shows how to allow IP multicast routing in a multicast-capable internetwork between two broadcast-only internetworks.
In this example, assume that a server on the LAN connected to the Ethernet interface 0 of the first hop router is sending a UDP broadcast stream with a source address of 126.1.22.199 and a destination address of 126.1.22.255:4000. Based on that scenario, the configuration on the first hop router converts the broadcast stream arriving at incoming Ethernet interface 0 destined for UDP port 4000 to a multicast stream. The access list permits traffic being sent from the server at 126.1.22.199 being sent to 126.1.22.255:4000. The traffic is sent to group address 239.254.2.5. The ip forward-protocol command specifies the forwarding of broadcast messages destined for UDP port 4000.
The second configuration on the last hop router converts the multicast stream arriving at incoming Ethernet interface 1 back to broadcast at outgoing Ethernet interface 2. Again, not all multicast traffic emerging from the multicast cloud should be converted from multicast to broadcast, only the traffic destined for 126.1.22.255:4000.
The configurations for the first and last hop routers are as follows:
First Hop Router Configuration
interface ethernet 0ip address 126.1.22.1 255.255.255.0ip pim sparse-modeip multicast helper-map broadcast 239.254.2.5 105access-list 105 permit udp host 126.1.22.199 host 126.1.22.255 eq 4000ip forward-protocol udp 4000Last Hop Router Configuration
interface ethernet 1ip address 126.1.26.1 255.255.255.0ip pim sparse-modeip multicast helper-map 239.254.2.5 126.1.28.255 105interface ethernet 2ip address 126.1.28.1 255.255.255.0ip directed-broadcastaccess-list 105 permit udp host 126.1.22.199 any eq 4000ip forward-protocol udp 4000Related Commands
ip multicast mrinfo-filter
To filter multicast router information (mrinfo) request packets, use the ip multicast mrinfo-filter command in global configuration mode. To remove the filter on mrinfo requests, use the no form of this command.
ip multicast mrinfo-filter access-list
no ip multicast mrinfo-filter access-list
Syntax Descriptionno ip multicast mrinfo-filter access-list
access-list
IP standard numbered or named access list that determines which network or hosts can query the local multicast router with the mrinfo command.
Defaults
No default behavior or values
Command Modes
Global configuration
Command History
12.0(23)S
This command was introduced.
12.2(13)T
This command was integrated into Cisco IOS Release 12.2(13)T.
Usage Guidelines
The ip multicast mrinfo-filter command filters the mrinfo request packets from all of the sources permitted by the specified access list. That is, if the access list permits a source, that source's mrinfo requests are filtered. For all sources that the access list explicitly or implicitly denies, the mrinfo requests are allowed to proceed.
Examples
The following example specifies that mrinfo request packets from all hosts on network 192.178.1.0 are not allowed to be processed by the router:
ip multicast mrinfo-filter 4access-list 4 permit 192.178.1.0 0.0.0.255Related Commands
mrinfo
Queries a multicast router about which neighboring multicast routers are peering with it.
ip multicast multipath
To enable load splitting of IP multicast traffic across multiple equal-cost paths, use the ip multicast multipath command in global configuration mode. To disable this configuration, use the no form of this command.
ip multicast [vrf vrf-name] multipath
no ip multicast [vrf vrf-name] multipath
Syntax Description
vrf
(Optional) Supports the multicast VPN routing and forwarding (VRF) instance.
vrf-name
(Optional) Name assigned to the VRF.
Defaults
By default, if multiple equal-cost paths exist, multicast traffic will not be load split across these paths.
Command Modes
Global configuration
Command History
Usage Guidelines
If the ip multicast multipath command is configured and multiple equal-cost paths exist, load splitting will occur across the equal-cost paths for multicast traffic from different sources to the same multicast group, but not for traffic from the same source to different multicast groups. Because this command changes the way a Reverse Path Forwarding (RPF) neighbor is selected, it must be configured consistently on all routers in a redundant topology to avoid looping.
Examples
The following example shows how to configure the ip multicast multipath command:
ip multicast multipathRelated Commands
ip multicast rate-limit
To control the rate a sender from the source list can send to a multicast group in the group list, use the ip multicast rate-limit command in interface configuration mode. To remove the control, use the no form of this command.
ip multicast rate-limit {in | out} [video | whiteboard] [group-list access-list] [source-list access-list] kbps
no ip multicast rate-limit {in | out} [video | whiteboard] [group-list access-list] [source-list access-list] kbps
Syntax Description
Defaults
If this command is not configured, there is no rate limit.
If this command is configured, the kbps value defaults to 0, meaning that no traffic is permitted.Command Modes
Interface configuration
Command History
Usage Guidelines
If a router receives a packet the user has sent over the limit, the packet is dropped; otherwise, it is forwarded.
For the video or whiteboard keyword to work, the ip sap listen command must be enabled so that the port number can be obtained from the SAP cache. If the ip sap listen command is not enabled, or the group address is not in the SAP cache, no rate-limiting is done for the group.
Examples
In the following example, packets to any group from sources in network 172.16.0.0 will have their packets rate-limited to 64 kbps:
interface serial 0ip multicast rate-limit out group-list 1 source-list 2 64access-list 1 permit 0.0.0.0 255.255.255.255access-list 2 permit 172.16.0.0 0.0.255.255Related Commands
ip sap listen
Enables the Cisco IOS software to listen to session directory advertisements.
ip multicast route-limit
To limit the number of multicast routes (mroutes) that can be added to a multicast routing table, use the ip multicast route-limit command in global configuration mode. To disable this configuration, use the no form of this command.
ip multicast [vrf vrf-name] route-limit limit [threshold]
no ip multicast [vrf vrf-name] route-limit limit [threshold]
Syntax Description
Defaults
limit: 2147483647
Command Modes
Global configuration
Command History
12.0(23)S
This command was introduced.
12.2
This command was integrated into Cisco IOS Release 12.2.
Usage Guidelines
The ip multicast route-limit command limits the number of multicast routes that can be added to a router and generates an error message when the limit is exceeded. If the user sets the threshold argument, a threshold error message is generated when the threshold is exceeded, and the message continues to occur until the number of mroutes reaches the limit set by the limit argument.
The mroute warning threshold must not exceed the mroute limit.
Examples
The following example sets the mroute limit at 200,000 and the threshold at 20,000 for a VRF instance named cisco:
ip multicast vrf cisco route-limit 200000 20000ip multicast rpf backoff
To configure the intervals at which Protocol Independent Multicast (PIM) Reverse Path Forwarding (RPF) failover will be triggered by changes in the routing tables, use the ip multicast rpf backoff command in global configuration mode. To set the triggered RPF check to the default values, use the no form of this command.
ip multicast rpf backoff minimum maximum [disable]
no ip multicast rpf backoff minimum maximum [disable]
Syntax Description
Defaults
This command is enabled by default.
minimum: 500 ms.
maximum: 5000 ms.Command Modes
Global configuration
Command History
Usage Guidelines
In an unstable unicast routing environment that uses triggered RPF checks, the environment could be constantly triggering RPF checks, which places a burden on the resources of the router. To avoid this problem, use the ip multicast rpf backoff command to prevent a second triggered RPF check from occurring for the length of time configured. That is, the PIM "backs off" from another triggered RPF check for a minimum amount of milliseconds as configured by the user.
If the backoff period expires without further routing table changes, PIM then scans for routing changes and accordingly establishes multicast RPF changes. However, if more routing changes occur during the backoff period, PIM doubles the backoff period to avoid overloading the router with PIM RPF changes while the routing table is still converging.
Note
The maximum argument is used to configure the maximum backoff interval. The backoff time is reset to the time configured by the minimum argument if an entire backoff interval has expired without routing changes.
The maximum argument default allows the RPF change behavior to be backward-compatible, allowing a 5-second RPF check interval in case of frequent route changes and a 500-ms RPF check interval in stable networks with only unplanned routing changes. Before the introduction of the ip multicast rpf backoff command, PIM polled the routing tables for changes every 5 seconds.
You likely need not change the defaults of the ip multicast rpf backoff command unless you have frequent route changes in your router (for example, on a dial-in router). Changing the defaults can allow you to reduce the maximum RPF check interval for faster availability of IP multicast on newly established routes or to increase the maximum RPF check interval to reduce the CPU load caused by the RPF check.
Examples
The following example configures the minimum backoff interval at 100 ms and the maximum backoff interval at 2500 ms:
ip multicast rpf backoff 100 2500ip multicast rpf interval
To modify the intervals at which periodic Reverse Path Forwarding (RPF) checks occur, use the ip multicast rpf interval command in global configuration mode. To return to the default interval, use the no form of this command.
ip multicast rpf interval seconds [list access-list | route-map route-map]
no ip multicast rpf interval seconds [list access-list | route-map route-map]
Syntax Description
Defaults
This command is enabled by default.
seconds: 10Command Modes
Global configuration
Command History
Usage Guidelines
You can configure multiple instances of this command by using an access list or a route map.
Note
Examples
The following example sets the periodic RPF check interval to 10 seconds:
ip multicast rpf interval 10The following example sets a periodic RPF check interval of 3 seconds for groups that are defined by access list 10:
ip multicast rpf interval 3 list 10The following example sets a periodic RPF check interval of 2 seconds for groups that are defined by the route map named map:
ip multicast rpf interval 2 route-map mapRelated Commands
ip igmp query-interval
Configures the frequency at which the Cisco IOS software sends IGMP host hello messages.
ip multicast ttl-threshold
To configure the time-to-live (TTL) threshold of packets being forwarded out an interface, use the ip multicast ttl-threshold command in interface configuration mode. To return to the default TTL threshold, use the no form of this command.
ip multicast ttl-threshold ttl-value
no ip multicast ttl-threshold ttl-value
Syntax Description
ttl-value
Time-to-live value, in hops. It can be a value from 0 to 255. The default value is 0, which means that all multicast packets are forwarded out the interface.
Defaults
The default TTL value is 0, which means that all multicast packets are forwarded out the interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
Only multicast packets with a TTL value greater than the threshold are forwarded out the interface.
You should configure the TTL threshold only on border routers. Conversely, routers on which you configure a TTL threshold value automatically become border routers.
This command replaces the ip multicast-threshold command.
Examples
The following example sets the TTL threshold on a border router to 200, which is a very high value. In this example multicast packets must have a TTL greater than 200 in order to be forwarded out this interface. Multicast applications generally set this value well below 200. Therefore, setting a value of 200 means that no packets will be forwarded out the interface.
interface tunnel 0ip multicast ttl-threshold 200ip multicast use-functional
To enable the mapping of IP multicast addresses to the Token Ring functional address 0xc000.0004.0000, use the ip multicast use-functional command in interface configuration mode. To disable the function, use the no form of this command.
ip multicast use-functional
no ip multicast use-functional
Syntax Description
This command has no arguments or keywords.
Defaults
IP multicast address are mapped to the MAC-layer address 0xFFFF.FFFF.FFFF.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is accepted only on a Token Ring interface.
Neighboring devices on the Token Ring on which this feature is used should also use the same functional address for IP multicast traffic.
Because there are a limited number of Token Ring functional addresses, other protocols may be assigned to the Token Ring functional address 0xc000.0004.0000. Therefore, not every frame sent to the functional address is necessarily an IP multicast frame.
Examples
The following example configures any IP multicast packets going out Token Ring interface 0 to be mapped to MAC address 0xc000.0004.0000:
interface token 0ip address 10.0.0.0 255.255.255.0ip pim dense-modeip multicast use-functionalip multicast-routing
To enable IP multicast routing, use the ip multicast-routing command in global configuration mode. To disable IP multicast routing, use the no form of this command.
ip multicast-routing [vrf vrf-name] [distributed]
no ip multicast-routing [vrf vrf-name]
Syntax Description
Defaults
IP multicast routing is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
When IP multicast routing is disabled, the Cisco IOS software does not forward any multicast packets.
Examples
The following example shows how to enable IP multicast routing:
Router(config)# ip multicast-routingRelated Commands
