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Cisco IOS IP Multicast Command Reference
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beacon (multicast routing monitor) through ip dvmrp summary-address
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ip dvmrp unicast-routing through ip igmp ssm-map query dns
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ip igmp ssm-map static through ip multicast rate-limit
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ip multicast route-limit through ip pim state-refresh origination-interval
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ip pim vc-count through show ip igmp snooping statistics
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show ip igmp ssm-mapping through udp-port
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Table Of Contents
ip pim snooping (global configuration)
ip pim snooping (interface configuration)
ip pim snooping suppress sgr-prune
ip pim state-refresh origination-interval
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
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 shows how to set the mroute limit to 200,000 and the threshold to 20,000 mroutes for a VRF instance named test:
ip multicast vrf test 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
Command Default
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
We recommend that users keep the default values for this command. The default values allow subsecond RPF failover.
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 shows how to set the minimum backoff interval to 100 ms and the maximum backoff interval to 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
Command Default
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 shows how to set the periodic RPF check interval to 10 seconds:
ip multicast rpf interval 10The following example shows how to set the periodic RPF check interval for groups that are defined by access list 10 to 3 seconds:
ip multicast rpf interval 3 list 10The following example shows how to set the periodic RPF check interval for groups that are defined by the route map named map to 2 seconds:
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 rpf proxy vector
To enable a provider edge (PE) router to perform a Reverse Path Forwarding (RPF) check on an IP address of the exit router in the global table or a specific VPN, use the ip multicast rpf proxy vector command in global configuration mode. To disable this functionality, use the no form of this command.
ip multicast [vrf vrf-name] rpf proxy [rd] vector
no ip multicast [vrf vrf-name] rpf proxy [rd] vector
Syntax Description
Defaults
The RPF Vector functionality is disabled.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
Use the ip multicast rpf proxy vector command to enable a PE router to perform an RPF check on an IP address of the exit router in the global table or a specified VPN.
RPF Vector Functionality
Normally, in an MVPN environment, PIM sends join messages containing the IP address of upstream PE routers that are sources of a given Multicast Distribution Tree (MDT) group. To be able to perform RPF checks, however, provider (P) routers must have IPv4 reachability to source PE routers in remote autonomous systems. This behavior is not the case with inter-AS Options B and C (defined in RFC 4364) because the autonomous systems do not exchange any of their Interior Gateway Protocol (IGP) routes, including those of their local PE routers. However, P routers do have reachability to the BGP next hop of the BGP MDT update received with the BGP MDT Subaddress Family Identifier (SAFI) updates at the PE routers. Therefore, if the PE routers add the remote PE router IP address (as received within the BGP MDT SAFI) and the BGP next-hop address of this address within the PIM join, the P routers can perform an RPF check on the BGP next-hop address rather than the original PE router address, which, in turn, allows the P router to forward the join toward the Autonomous System Border Router (ASBR) that injected the MDT SAFI updates for a remote autonomous system. This functionality is generally referred to as the PIM RPF Vector; the actual vector that is inserted into PIM joins is referred to as the RPF Vector or the Proxy Vector. The PIM RPF Vector, therefore, enables P routers to determine the exit ASBR to a source PE router in a remote autonomous system. Having received the join that contains a RPF Vector, an ASBR can then determine that the next-hop address is in fact itself and can perform an RPF check based on the originating PE router address carried in the PIM join.
RPF Vector Configuration Guidelines
When configured on PE routers using the ip multicast rpf proxy vector command, the RPF Vector is encoded as a part of the source address in PIM join and prune messages. The RPF Vector is the IGP next hop for PIM RPF neighbor in PIM join and prune messages, which is typically the exit ASBR router to a prefix in a remote autonomous system.
When enabling the RPF Vector on PE routers in Option B deployments, the following form of the ip multicast rpf proxy vector command should be used:
ip multicast vrf vrf-name rpf proxy rd vector
This form of the command enables an PE router to perform RPF checks on an IP address of the exit router for a specific VPN. The rd keyword is used in this form of the command to configure PE routers to include the RD value of the VPN associated with the PIM RPF Vector encoding inserted into PIM join and prune messages. Because ASBRs in Option B deployments change the next hop of the originating PE router for a given MDT group, including the RD value in the PIM RPF Vector encoding enables the ASBR to perform a lookup on the RD value for a prefix, which, in turn, enables the ASBR to identify which VPN the RPF Vector is intended for.
When enabling the RPF Vector on PE routers in Option C deployments, the following form of the ip multicast rpf proxy vector command should be used:
ip multicast rpf proxy vector
This form of the command enables the PE router to perform RPF checks on an IP address of the exit router in the global table.
RPF Vector Verification
Use the show ip pim neighbor command to verify that a PIM neighbor supports the RPF Vector functionality. The P flag in the output of the show ip pim neighbor command indicates that a PIM neighbor has announced (through PIM hello messages) its capability to handle RPF Vectors in PIM join messages. All Cisco IOS versions that support the PIM RPF Vector feature announce this PIM hello option. An RPF Vector is only included in PIM messages when all PIM neighbors on an RPF interface support it.
Examples
The following example shows how to enable a PE router to perform RPF checks on the IP address of the exit router in the global table:
ip multicast rpf proxy vectorRelated Commands
ip multicast rpf select
To configure Reverse Path Forwarding (RPF) lookups originating in a receiver Multicast VPN (MVPN) routing and forwarding (MVRF) instance or in the global routing table to be performed in a source MVRF instance or in the global routing table based on group address, use the ip multicast rpf select command. To disable the functionality, use the no form of the command.
ip multicast [vrf receiver-vrf-name] rpf select {global | vrf source-vrf-name} group-list access-list
no ip multicast [vrf receiver-vrf-name] rpf select {global | vrf source-vrf-name} group-list access-list
Syntax Description
Command Default
No group-based VRF selection policies are configured.
Command Modes
User EXEC
Privileged EXECCommand History
Usage Guidelines
Use the ip multicast rpf select command to configure group-based VRF selection policies. By defining group-based VRF selection policies, you can configure the RPF lookups originating in a receiver MVRF or in the global routing table to be performed in a source MVRF or in the global routing table based on group address. ACLs are used to define the groups to be applied to a group-based VRF selection policy.
Use the show ip rpf select command after configuring group-based VRF selection policies to display group-to-VRF mapping information.
Use the show ip rpf command to display how IP multicast does RPF.
Examples
The following example shows how to use a group-based VRF selection policy to configure the RPF lookup for groups that match ACL 1 to be performed in VPN-A instead of the global table:
ip multicast rpf select vrf VPN-A group-list 1!...!access-list 1 permit 239.0.0.0 0.255.255.255!Related Commands
show ip rpf
Displays how IP multicast routing does RPF.
show ip rpf select
Displays group-to-VRF mapping information.
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-routingThe following example shows how to enable IP multicast routing on a specific VRF:
Router(config)# ip multicast-routing vrf vrf1The following example shows how to disable IP multicast routing:
Router(config)# no ip multicast-routingRelated Commands
ip pgm host
Note
To enable Pragmatic General Multicast (PGM) Host, use the ip pgm host command in global configuration mode. To disable PGM Host and close all open PGM Host traffic sessions, use the no form of this command.
ip pgm host [source-interface {interface-type interface-number} | connection-parameter]
no ip pgm host
Syntax Description
source-interface interface-type interface-number
(Optional) Specifies the interface type and number on which to run PGM Host.
connection-parameter
(Optional) Configures advanced PGM Host connection parameters. The optional configuration parameters should be configured only by experts in PGM technology. See Table 8 for a comprehensive list of the optional connection parameters and their definitions.
Defaults
PGM Host is not enabled.
Command Modes
Global configuration
Command History
Usage Guidelines
Using the ip pgm host command without a keyword or an argument enables PGM Host on the router and configures the router to source PGM packets through a virtual host interface.
Specifying a physical or logical interface type (for example, an Ethernet, serial, or loopback interface) with the ip pgm host source-interface command configures the router to source PGM packets out of the physical or logical interface.
Note
Sourcing PGM packets through a virtual host interface enables the router to send and receive PGM packets through any router interface. The virtual host interface also serves as the interface to the multicast applications that reside at the PGM network layer.
Sourcing IP multicast traffic out a specific physical or logical interface configures the router to send PGM packets out that interface only and to receive packets on any router interface.
When both PGM Host and Router Assist are enabled on the router, the router can process received PGM packets as a virtual PGM Host, originate PGM packets and serve as its own first hop PGM network element, and forward received PGM packets. Refer to the "Configuring PGM Host and Router Assist" chapter of the Cisco IOS IP Configuration Guide for more information about PGM Router Assist.
Table 8 lists the available parameters for the connection-parameter argument. The parameters should be configured only by experts in PGM technology. Use the no ip pgm host connection-parameter command to return a parameter to its default value.
Examples
The following example enables PGM Host (both the source and receiver part of the PGM network layer) globally on the router and configures the router to source PGM packets through a virtual host interface:
ip pgm hostThe following example enables PGM Host globally on the router and configures the router to source PGM packets out of physical Ethernet interface 0/1:
ip pgm hostip pgm host source-interface ethernet 0/1Related Commands
ip pgm router
To enable Pragmatic General Multicast (PGM) Router Assist and thereby allow PGM to operate more efficiently on the router, use the ip pgm router command in interface configuration mode. To disable PGM Router Assist for the interface, use the no form of this command.
ip pgm router
no ip pgm router
Syntax Description
This command has no arguments or keywords.
Defaults
PGM Router Assist is disabled for the interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is highly recommended for optimal deployment of PGM Reliable Transport Protocol on a host.
Examples
In the following example, PGM Router Assist is configured on Ethernet interfaces 0 and 1:
ip multicast-routinginterface ethernet 0ip pim sparse-dense-modeip pgm routerinterface ethernet 1ip pim sparse-dense-modeip pgm routerRelated Commands
clear ip pgm router
Clears PGM traffic statistics.
ip pgm host
Enables PGM Host.
show ip pgm router
Displays PGM Reliable Transport Protocol state and statistics.
ip pim
To enable Protocol Independent Multicast (PIM) on an interface, use the ip pim command in interface configuration mode. To disable PIM on the interface, use the no form of this command.
ip pim {sparse-mode | sparse-dense-mode | dense-mode [proxy-register {list access-list | route-map map-name}]}
no ip pim {sparse-mode | sparse-dense-mode | dense-mode [proxy-register {list access-list | route-map map-name}]}
Syntax Description
Defaults
IP multicast routing is disabled on all interfaces.
Command Modes
Interface configuration
Command History
Usage Guidelines
Enabling PIM on an interface also enables Internet Group Management Protocol (IGMP) operation on that interface. An interface can be configured to be in dense mode, sparse mode, or sparse-dense mode. The mode describes how the Cisco IOS software populates its multicast routing table and how the software forwards multicast packets it receives from its directly connected LANs. Dense mode interfaces are always added to the table when the multicast routing table is populated. Sparse mode interfaces are added to the table only when periodic join messages are received from downstream routers, or there is a directly connected member on the interface.
Dense Mode
Initially, a dense mode interface forwards multicast packets until the router determines that there are group members or downstream routers, or until a prune message is received from a downstream router. Then, the dense mode interface periodically forwards multicast packets out the interface until the same conditions occur. Dense mode assumes that multicast group members are present. Dense mode routers never send a join message. They do send prune messages as soon as they determine they have no members or downstream PIM routers. A dense mode interface is subject to multicast flooding by default.
Dense Mode with Proxy Registering
For a router in a PIM sparse mode (PIM-SM) domain configured to operate in sparse mode or sparse-dense mode, the ip pim dense-mode proxy-register command must be configured on the interface leading toward the bordering dense mode region. This configuration will enable the router to register traffic from the dense mode region with the rendezvous point (RP) in the sparse mode domain.
Prior to Cisco IOS Release 12.0 S, an RP needed to be running on the border router leading toward a dense mode region so that the RP could learn about traffic from sources in the dense mode region.
This command requires an extended access list or route map argument specifying which traffic the router needs to register with the RP. This command applies only to sources reachable through a PIM router. Cisco IOS software will always register traffic from remote sources if it arrives on a dense mode interface and if the Reverse Path Forwarding (RPF) neighbor leading toward the source is a Distance Vector Multicast Routing Protocol (DVMRP) but not a PIM router. This functionality has existed since Cisco IOS Release 10.0 and cannot be modified (restricted) with an access list or route map.
Sparse Mode
A sparse mode interface is used for multicast forwarding only if a join message is received from a downstream router or if group members are directly connected to the interface. Sparse mode assumes that no other multicast group members are present. When sparse mode routers want to join the shared path, they periodically send join messages toward the RP. When sparse mode routers want to join the source path, they periodically send join messages toward the source; they also send periodic prune messages toward the RP to prune the shared path.
Sparse-Dense Mode
An alternative to choosing just dense mode or just sparse mode is to run PIM in a single region in sparse mode for some groups and dense mode for other groups.
In sparse-dense mode, if the group is in dense mode, the interface will be treated as dense mode. If the group is in sparse mode, the interface will be treated in sparse mode. The group is "sparse" if the router knows about an RP for that group.
When an interface is treated in dense mode, it is populated in the outgoing interface list of the multicast routing table when either of the following conditions is true:
•
•
When an interface is treated in sparse mode, it is populated in the outgoing interface list of the multicast routing table when either of the following conditions is true:
•
•
Examples
The following example shows how to enable PIM-SM on tunnel interface 0 and set the address of the RP router to 226.0.0.8:
ip pim rp-address 226.0.0.8interface tunnel 0ip pim sparse-modeThe following example shows how to enable PIM dense mode (PIM-DM) on Ethernet interface 1:
interface ethernet 1ip pim dense-modeThe following example shows how to enable PIM sparse-dense mode on Ethernet interface 1:
interface ethernet 1ip pim sparse-dense-modeThe following example shows how to register the multicast traffic for any source and any multicast group:
interface ethernet 0ip address 172.16.0.0 255.255.255.0description Ethernet interface towards the PIM sparse-mode domainip pim sparse-dense-mode!interface ethernet 1ip address 192.44.81.5 255.255.255.0description Ethernet interface towards the PIM dens-mode regionip pim dense-mode proxy-register list 100!access-list 100 permit ip any anyRelated Commands
ip pim accept-register
To configure a candidate rendezvous point (RP) router to filter Protocol Independent Multicast (PIM) register messages, use the ip pim accept-register command in global configuration mode. To remove the PIM register filter, use the no form of this command.
ip pim [vrf vrf-name] accept-register {list access-list | route-map map-name}
no ip pim [vrf vrf-name] accept-register {list access-list | route-map map-name}
Syntax Description
Command Default
No PIM register filters are configured.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
Use this command to prevent unauthorized sources from registering with the RP. If an unauthorized source sends a register message to the RP, the RP will immediately send back a register-stop message.
The access list or route map provided for the ip pim accept-register command should only filter on IP source addresses and IP destination addresses. Filtering on other fields (for example, IP protocol or UDP port number) will not be effective and may cause undesired traffic to be forwarded from the RP down the shared tree to multicast group members. If more complex filtering is desired, use the ip multicast boundary command instead.
Note
Examples
The following example shows how to permit register packets for source address 172.16.10.1 sending to the SSM group range (232.0.0.0/8). All other PIM register messages not matching the extended access list (ssm-range) are denied. These statements should be configured on all candidate RPs because candidate RPs will receive PIM registers from first hop routers.
ip pim accept-register list ssm-rangeip access-list extended ssm-rangepermit ip 172.16.10.1 0.0.0.255 232.0.0.0 0.255.255.255Related Commands
ip multicast boundary
Configures an administratively scoped IPv4 multicast boundary.
ip pim accept-rp
To configure a router to accept join or prune messages destined for a specified rendezvous point (RP) and for a specific list of groups, use the ip pim accept-rp command in global configuration mode. To remove that check, use the no form of this command.
ip pim [vrf vrf-name] accept-rp {rp-address | auto-rp} [access-list]
no ip pim [vrf vrf-name] accept-rp {rp-address | auto-rp} [access-list]
Syntax Description
Defaults
The command is disabled, so all join messages and prune messages are processed.
Command Modes
Global configuration
Command History
Usage Guidelines
This command causes the router to accept only (*, G) join messages destined for the specified RP address. Additionally, the group address must be in the range specified by the access list.
When the rp-address argument is one of the addresses of the system, the system will be the RP only for the specified group range specified by the access list. When the group address is not in the group range, the RP will not accept join or register messages and will respond immediately to register messages with register-stop messages.
Examples
The following example shows how to configure the router to accept join or prune messages destined for the RP at address 172.17.1.1 for the multicast group 224.2.2.2:
ip pim accept-rp 172.17.1.1 3access-list 3 permit 224.2.2.2Related Commands
ip pim autorp listener
To cause IP multicast traffic for the two Auto-RP groups 224.0.1.39 and 224.0.1.40 to be Protocol Independent Multicast (PIM) dense mode flooded across interfaces operating in PIM sparse mode, use the ip pim autorp listener command in global configuration mode. To disable this feature, use the no form of this command.
ip pim autorp listener
no ip pim autorp listener
Syntax Description
This command has no arguments or keywords.
Defaults
This command is disabled by default.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip pim autorp listener command with interfaces configured for PIM sparse mode operation in order to establish a network configuration where Auto-RP operates in PIM dense mode and multicast traffic can operate in sparse mode, bidirectional mode, or Source Specific Multicast (SSM) mode.
Examples
The following example enables IP multicast routing and the Auto-RP listener feature on a router. It also configures the router as a candidate RP for the multicast groups 239.254.2.0 through 239.254.2.255.
ip multicast-routingip pim autorp listenerip pim send-rp-announce Loopback0 scope 16 group-list 1ip pim send-rp-discovery Loopback1 scope 16access-list 1 permit 239.254.2.0 0.0.0.255ip pim bidir-enable
To enable bidirectional Protocol Independent Multicast (bidir-PIM), use the ip pim bidir-enable command in global configuration mode. To disable bidir-PIM, use the no form of this command.
ip pim [vrf vrf-name] bidir-enable
no ip pim [vrf vrf-name] bidir-enable
Syntax Description
vrf
(Optional) Supports the multicast Virtual Private Network (VPN) routing and forwarding (VRF) instance.
vrf-name
(Optional) Name assigned to the VRF.
Defaults
The command is enabled.
Command Modes
Global configuration
Command History
Usage Guidelines
Bidir-PIM is disabled by default to ensure complete backward compatibility when upgrading a router to Cisco IOS Release 12.0(18)ST or a later release.
When bidir-PIM is disabled, the router will behave similarly to a router without bidir-PIM support. The following conditions will apply:
•
•
•
–
–
•
Examples
The following example shows how to configure a rendezvous point (RP) for both sparse mode and bidirectional mode groups: 224/8 and 227/8 are bidirectional groups, 226/8 is sparse mode, and 225/8 is dense mode. The RP must be configured to use different IP addresses for the sparse mode and bidirectional mode operations. Two loopback interfaces are used to allow this configuration. The addresses of these loopback interfaces must be routed throughout the PIM domain such that the other routers in the PIM domain can receive Auto-RP announcements and communicate with the RP.
ip multicast-routingip pim bidir-enable!interface loopback 0description One Loopback adddress for this routers Bidir Mode RP functionip address 10.0.1.1 255.255.255.0ip pim sparse-dense-mode!interface loopback 1description One Loopback adddress for this routers Sparse Mode RP functionip address 10.0.2.1 255.255.255.0ip pim sparse-dense-modeip pim send-rp-announce Loopback0 scope 10 group-list 45 bidirip pim send-rp-announce Loopback1 scope 10 group-list 46ip pim send-rp-discovery scope 10access-list 45 permit 224.0.0.0 0.255.255.255access-list 45 permit 227.0.0.0 0.255.255.255access-list 45 deny 225.0.0.0 0.255.255.255access-list 46 permit 226.0.0.0 0.255.255.255Related Commands
ip pim bidir-neighbor-filter
To configure an access list (ACL) to specify which bidirectionally capable (bidir-capable) neighbors will participate in the designated forwarder (DF) election, use the ip pim bidir-neighbor-filter command in interface configuration mode. To allow all neighbors to participate in DF election, use the no form of this command.
ip pim bidir-neighbor-filter acl-name
no ip pim bidir-neighbor-filter acl-name
Syntax Description
Defaults
All routers are considered to be bidirectional (bidir) capable.
Command Modes
Interface configuration
Command History
Usage Guidelines
Normally, DF election only occurs on those interfaces on which all Protocol Independent Multicast (PIM) neighbors are bidir capable. To allow for a smoother transition from a sparse-mode only network to a hybrid bidir-/sparse-mode network, the ip pim bidir-neighbor-filter command enables you to specify what routers should be participating on the DF election, while still allowing all routers to participate in the sparse-mode domain.
Bidirectional PIM allows multicast routers to keep reduced state information. All of the multicast routers in a segment must be bidirectionally enabled in order for bidir to elect a DF. Because routers in a segment are not always bidir-enabled, a mechanism is necessary to allow these routers to elect a DF from those routers on a segment that are bidir-enabled.
Multicast boundaries on the nonbidir routers are defined to prevent PIM messages and data for the bidir groups to leak in or out of the bidir subset cloud. Meanwhile, the bidir routers can elect a DF from among themselves even when there are nonbidir routers in the segment.
The ip pim bidir-neighbor-filter command allows the use of an ACL to specify which neighbors will participate in the DF election, allowing bidir deployment in the necessary routers without having to upgrade all of the routers in the segment.
Default behavior is that all routers are considered to be bidir-capable. Therefore, if one neighbor does not support bidir, the DF election will not occur.
When the ip pim bidir-neighbor-filter command is enabled, the routers that are permitted by the ACL are considered to be bidir-capable. Therefore:
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Examples
In the following example, the neighbor at address 10.4.0.3 is considered to be bidir-capable:
Router# show ip pim neighbor ethernet 3/3PIM Neighbor TableNeighbor Interface Uptime/Expires Ver DRAddressPrio/Mode10.4.0.4 Ethernet3/3 00:01:52/00:01:20 v2 1 / DR B10.4.0.3 Ethernet3/3 00:01:52/00:01:20 v2 1 / BRouter# show access-lists 50Standard IP access list 5010 permit 10.4.0.4 (3 matches)20 deny 10.4.0.3 (7 matches)The ip pim bidir-neighbor-filter 50 command sets conditions for DF election through use of ACL 50.
Router(config) interface ethernet 3/3Router(config-if)# ip pim bidir-neighbor-filter 50The following example shows the neighbor router at address 10.4.0.4 is now permitted to participate in DF election, and the neighbor router at address 10.4.0.3 is now denied access to DF election:
Router# show run interface ethernet 3/3Building configuration...Current configuration :210 bytes!interface Ethernet3/3ip address 10.4.0.2 255.255.0.0no ip redirectsno ip proxy-arpip pim bidir-neighbor-filter 50ip pim sparse-dense-modeno ip route-cache cefno ip route-cacheduplex halfendRouter# show ip pim neighbor ethernet 3/3PIM Neighbor TableNeighbor Interface Uptime/Expires Ver DRAddressPrio/Mode10.4.0.4 Ethernet3/3 00:04:03/00:01:39 v2 1 / DR B10.4.0.3 Ethernet3/3 00:04:03/00:01:38 v2 1 /ip pim border
The ip pim border command is replaced by the ip pim bsr-border command. See the description of the ip pim bsr-border command for more information.
ip pim bsr-border
To prevent bootstrap router (BSR) messages from being sent or received through an interface, use the ip pim bsr-border command in interface configuration mode. To disable this configuration, use the no form of this command.
ip pim bsr-border
no ip pim bsr-border
Syntax Description
This command has no arguments or keywords.
Defaults
The command is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
When this command is configured on an interface, no Protocol Independent Multicast (PIM) Version 2 BSR messages will be sent or received through the interface. Configure an interface bordering another PIM domain with this command to avoid BSR messages from being exchanged between the two domains. BSR messages should not be exchanged between different domains, because routers in one domain may elect rendezvous points (RPs) in the other domain, resulting in protocol malfunction or loss of isolation between the domains.
Note
Examples
The following example configures the interface to be the PIM domain border:
interface ethernet 1ip pim bsr-borderRelated Commands
ip multicast boundary
Configures an administratively scoped boundary.
ip pim bsr-candidate
Configures the router to announce its candidacy as a BSR.
ip pim bsr-candidate
To configure the router to announce its candidacy as a bootstrap router (BSR), use the ip pim bsr-candidate command in global configuration mode. To remove this router as a candidate for being a bootstrap router, use the no form of this command.
ip pim [vrf vrf-name] bsr-candidate interface-type interface-number [hash-mask-length] [priority]
no ip pim [vrf vrf-name] bsr-candidate interface-type interface-number [hash-mask-length] [priority]
Syntax Description
Defaults
The command is disabled.
priority: 0
Note
Command Modes
Global configuration
Command History
Usage Guidelines
This command causes the router to send bootstrap messages to all its PIM neighbors, with the address of the designated interface as the BSR address. Each neighbor compares the BSR address with the address it had from previous bootstrap messages (not necessarily received on the same interface). If the current address is the same or higher address, it caches the current address and forwards the bootstrap message. Otherwise, it drops the bootstrap message.
This router continues to be the BSR until it receives a bootstrap message from another candidate BSR saying that it has a higher priority (or if the same priority, a higher IP address).
Use this command only in backbone routers that have good connectivity to all parts of the PIM domain. That is, a stub router that relies on an on-demand dialup link to connect to the rest of the PIM domain is not a good candidate BSR.
You must enable the interface-type with PIM.
When you set the hash-mask-length argument, all groups with the same seed hash correspond to the same rendezvous point. For example, if this value is 24, only the first 24 bits of the group addresses are applicable; using this setting allows you to get one rendezvous point for multiple groups.
When you set the priority argument, the BSR with the larger priority is preferred. If the priority values are the same, the router with the larger IP address is the BSR.
Examples
The following example shows how to configure the IP address of the router on Ethernet interface 0/0 to be a candidate BSR with a priority of 192:
ip pim bsr-candidate ethernet 0/0 192Related Commands
ip pim dm-fallback
To enable Protocol Independent Multicast (PIM) dense mode (DM) fallback, use the ip pim dm-fallback command in global configuration mode. To prevent PIM dense mode fallback and to block all multicast traffic for groups not specifically configured, use the no form of this command.
ip pim dm-fallback
no ip pim dm-fallback
Syntax Description
This command has no arguments or keywords.
Command Default
PIM dense mode fallback is enabled. That is, a multicast group in the absence of rendezvous point (RP) information will fall to dense mode, regardless of the interface mode configuration.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
Use this command to prevent a router from falling back into PIM-DM when the RP becomes unavailable. This command also causes the router to block all multicast traffic for groups not specifically configured with an RP.
When IP multicast is used in mission-critical networks, you should avoid the use of PIM-DM. PIM makes the determination as to whether a multicast group operates in PIM-DM or PIM sparse-dense mode based solely on the existence of RP information in the group-to-RP mapping cache. If Auto-RP is configured or a bootstrap router (BSR) is used to distribute RP information, there is a risk that RP information can be lost if all RPs, Auto-RP, or the BSR for a group fails due to network congestion. This failure can lead to the network either partially or fully falling back into PIM-DM.
If a network falls back into PIM-DM, dense mode flooding will occur. Routers that lose RP information will switch all existing states into dense mode and any new states that must be created for the failed group will be created in dense mode.
Examples
The following example shows how to disable PIM-DM fallback:
no ip pim dm-fallbackRelated Commands
ip pim dense-mode
Enables PIM dense mode on the interface.
ip pim sparse-dense-mode
Enables PIM to operate in sparse or dense mode, depending on the group.
ip pim dr-priority
To set the priority for which a router is elected as the designated router (DR), use the ip pim dr-priority command in interface configuration mode. To disable this function, use the no form of this command.
ip pim dr-priority priority-value
no ip pim dr-priority priority-value
Syntax Description
priority-value
Value in the range from 0 to 4294967294 used to determine the priority of the router to be selected as the DR.
Defaults
The command is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
When a DR is a candidate for election, the following conditions apply:
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Examples
The following example sets the DR priority value of the Ethernet0 interface to 200:
interface Ethernet0ip address 10.0.1.2 255.255.255.0ip pim dr-priority 200ip pim minimum-vc-rate
To configure the minimum traffic rate to keep virtual circuits (VCs) from being idled, use the ip pim minimum-vc-rate command in interface configuration mode. To restore the default value, use the no form of this command.
ip pim minimum-vc-rate pps
no ip pim minimum-vc-rate
Syntax Description
pps
Rate, in packets per second, below which a VC is eligible for idling. The default value is 0, which means all VCs are eligible for idling. The range is from 0 to 4294967295.
Defaults
The default rate is 0 pps, which indicates all VCs are eligible for idling.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to an ATM interface only and also requires IP Protocol Independent Multicast sparse mode (PIM-SM).
An idling policy uses the ip pim vc-count number command to limit the number of VCs created by PIM. When the router stays at or below this number, no idling policy is in effect. When the next VC to be opened will exceed the number, an idling policy is exercised. Any virtual circuits with a traffic rate lower than the ip pim minimum-vc-rate command are subject to the idling policy.
Examples
The following example configures a minimum rate of 2500 pps over a VC, below which the VC is eligible for idling:
ip pim minimum-vc-rate 2500Related Commands
ip pim multipoint-signalling
To enable Protocol Independent Multicast (PIM) to open ATM multipoint switched virtual circuits (VCs) for each multicast group that a receiver joins, use the ip pim multipoint-signalling command in interface configuration mode. To disable the feature, use the no form of this command.
ip pim multipoint-signalling
no ip pim multipoint-signalling
Syntax Description
This command has no arguments or keywords.
Defaults
The command is disabled.
All multicast traffic goes to the static map multipoint VC as long as the atm multipoint-signalling command is configured.Command Modes
Interface configuration
Command History
Usage Guidelines
This command is accepted only on an ATM interface. It allows optimal multicast trees to be built down to ATM switch granularity. This command can enhance router performance and link utilization because packets are not replicated and sent multiple times over the ATM interface.
Examples
The following example enables PIM to open ATM multipoint switched VCs for each multicast group that is joined:
ip pim multipoint-signallingRelated Commands
ip pim nbma-mode
To configure a multiaccess WAN interface to be in nonbroadcast multiaccess (NBMA) mode, use the ip pim nbma-mode command in interface configuration mode. To disable this function, use the no form of this command.
ip pim nbma-mode
no ip pim nbma-mode
Syntax Description
This command has no arguments or keywords.
Defaults
The command is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command on Frame Relay, Switched Multimegabit Data Service (SMDS), or ATM only, especially when these media do not have native multicast available. Do not use this command on multicast-capable LANs such as Ethernet or FDDI.
When this command is configured, each Protocol Independent Multicast (PIM) join message is tracked in the outgoing interface list of a multicast routing table entry. Therefore, only PIM WAN neighbors that have joined for the group will get packets sent as data-link unicasts. This command should only be used when the ip pim sparse-mode command is configured on the interface. This command is not recommended for LANs that have natural multicast capabilities.
Examples
The following example configures an interface to be in NBMA mode:
ip pim nbma-modeRelated Commands
ip pim neighbor-filter
To prevent a router from participating in Protocol Independent Multicast (PIM) (for example, to configure stub multicast routing), use the ip pim neighbor-filter command in interface configuration mode. To remove the restriction, use the no form of this command.
ip pim neighbor-filter access-list
no ip pim neighbor-filter access-list
Syntax Description
Defaults
The command is disabled.
Command Modes
Interface configuration
Command History
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 query-interval
To configure the frequency of Protocol Independent Multicast (PIM) query (hello) messages, use the ip pim query-interval command in interface configuration mode. To return to the default interval, use the no form of this command.
ip pim query-interval period [msec]
no ip pim query-interval
Syntax Description
Command Default
PIM hello (query) messages are sent every 30 seconds.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to configure the frequency of PIM neighbor discovery messages. By default these messages are sent once every 30 seconds. In PIM Version 1 (PIMv1), these messages are referred to as PIM query messages; in PIM Version 2 (PIMv2), these messages are referred to as PIM hello messages. By default, routers run PIMv2 and send PIM hello messages. A router will change (auto-fallback) to PIMv1 and will send PIM query messages if it detects a neighboring router that only supports PIMv1. As soon as that neighboring PIMv1 router is removed from the network, the router will revert to PIMv2.
Note
Note
PIM neighbor discovery messages are used to determine which router on a network is acting as the Designated Router (DR) for PIM sparse mode (PIM-SM) and Source Specific Multicast (SSM). The DR is responsible for joining PIM-SM and SSM groups receiving multicast traffic from sources requested by receivers (hosts). In addition, in PIM-SM, the DR is also responsible for registering local sources with the RP. If the DR fails, a backup router will become the DR and then forward traffic for local receivers and register local sources.
The period argument is used to specify the PIM hello (query) interval. The interval determines the frequency at which PIM hello (query) messages are sent.
Note
The configured PIM hello interval also determines the holdtime used by a PIM router. The Cisco IOS software calculates the holdtime as follows:
3 * the interval specified for the period argument
By default, PIM routers announce the holdtime in PIM hello (query) messages.If the holdtime expires and another router has not received another hello (query) message from this router, it will timeout the PIM neighbor. If the timed out router was the DR, the timeout will trigger DR election. By default, the DR-failover interval occurs after 90 seconds (after the default holdtime expires for a DR). To reduce DR-failover time in redundant networks, a lower value for the period argument can be configured on all routers. The minimum DR-failover time that can be configured (in seconds) is 3 seconds (when the period argument is set to 1 second). The DR-failover time can be reduced to less than 3 seconds if the msecs keyword is specified. When the msecs keyword is used with the ip pim query-interval command, the value specified for the period argument is interpreted as a value in milliseconds (instead of seconds). By enabling a router to send PIM hello messages more often, this functionality allows the router to discover unresponsive neighbors more quickly. As a result, the router can implement failover or recovery procedures more efficiently
Note
Examples
The following example shows how to set the PIM hello interval to 45 seconds:
interface FastEthernet0/1ip pim query-interval 45The following example shows how to set the PIM hello interval to 100 milliseconds:
interface FastEthernet0/1ip pim query-interval 100 msecRelated Commands
show ip pim neighbor
Displays information about PIM neighbors discovered by PIMv1 router query messages or PIMv2 hello messages
ip pim register-rate-limit
To set a limit on the maximum number of Protocol Independent Multicast sparse mode (PIM-SM) register messages sent per second for each (S, G) routing entry, use the ip pim register-rate-limit command in global configuration mode. To disable this limit, use the no form of this command.
ip pim [vrf vrf-name] register-rate-limit rate
no ip pim [vrf vrf-name] register-rate-limit
Syntax Description
Defaults
No limit is defined.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to limit the number of register messages that the designated router (DR) will allow for each (S, G) entry. Enabling this command will limit the load on the DR and RP at the expense of dropping those register messages that exceed the set limit. Receivers may experience data packet loss within the first second in which register messages are sent from bursty sources.
If the ip pim command is configured with the dense-mode and proxy-register keywords, you must set a limit on the maximum number of PIM-SM register messages sent because of the potentially large number of sources from the dense mode area that may send data into the sparse mode region (and thus need registering in the border router).
This command applies only to sparse mode (S, G) multicast routing entries.
Examples
The following example shows how to configure the ip pim register-rate-limit command with a maximum rate of two register messages per second:
ip pim register-rate-limit 2Related Commands
ip pim register-source
To configure the IP source address of a register message to an interface address other than the outgoing interface address of the designated router (DR) leading toward the rendezvous point (RP), use the ip pim register-source command in global configuration mode. To disable this configuration, use the no form of this command.
ip pim [vrf vrf-name] register-source interface-type interface-number
no ip pim [vrf vrf-name] register-source
Syntax Description
Defaults
By default, the IP address of the outgoing interface of the DR leading toward the RP is used as the IP source address of a register message.
Command Modes
Global configuration
Command History
Usage Guidelines
This command is required only when the IP source address of a register message is not a uniquely routed address to which the RP can send packets. This situation may occur if the source address is filtered such that packets sent to it will not be forwarded or if the source address is not unique to the network. In these cases, the replies sent from the RP to the source address will fail to reach the DR, resulting in Protocol Independent Multicast sparse mode (PIM-SM) protocol failures.
If no IP source address is configured or if the configured source address is not in service, the IP address of the outgoing interface of the DR leading toward the RP is used as the IP source address of the register message. Therefore, we recommend using a loopback interface with an IP address that is uniquely routed throughout the PIM-SM domain.
Examples
The following example shows how to configure the IP source address of the register message to the loopback 3 interface of a DR:
ip pim register-source loopback 3ip pim rp-address
To statically configure the address of a Protocol Independent Multicast (PIM) rendezvous point (RP) for multicast groups, use the ip pim rp-address command in global configuration mode. To remove an RP address, use the no form of this command.
ip pim [vrf vrf-name] rp-address rp-address [access-list] [override] [bidir]
no ip pim [vrf vrf-name] rp-address rp-address [access-list] [override] [bidir]
Syntax Description
Command Default
No PIM static group-to-RP mappings are configured.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
In the Cisco IOS implementation of PIM, each multicast group individually operates in one of the following modes: dense mode, sparse mode, or bidirectional mode. Groups in sparse mode (PIM-SM) or bidirectional mode (bidir-PIM) use RPs to connect sources and receivers. All routers in a PIM domain need to have a consistent configuration for the mode and RP addresses of the multicast groups.
The Cisco IOS software learns the mode and RP addresses of multicast groups through the following three mechanisms: static group-to-RP mapping configurations, Auto-RP, and bootstrap router (BSR). By default, groups will operate in dense mode. No commands explicitly define groups to operate in dense mode.
Use the ip pim rp-address command to statically define the RP address for PIM-SM or bidir-PIM groups (an ip pim rp-address command configuration is referred to as a static group-to-RP mapping).
You can configure a single RP for more than one group using an access list. If no access list is specified, the static RP will map to all multicast groups, 224/4.
You can configure multiple RPs, but only one RP per group range.
If multiple ip pim rp-address commands are configured, the following rules apply:
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If dynamic and static group-to-RP mappings are used together, the following rule applies to a multicast group: Dynamic group-to-RP mappings take precedence over static group-to-RP mappings—unless the override keyword is used.
Examples
The following example shows how to set the PIM RP address to 192.168.0.1 for all multicast groups (224/4) and defines all groups to operate in sparse mode:
ip pim rp-address 192.168.0.1The following example shows how to set the bidir-PIM RP address to 172.16.0.2 for the multicast range 239/8.
access list 10 239.0.0.0 0.255.255.255ip pim rp-address 172.16.0.2 10 bidir
Note
ip pim rp-announce-filter
To filter incoming rendezvous point (RP) announcement messages sent from candidate RPs (C-RPs) to the RP mapping agent, use the ip pim rp-announce-filter command in global configuration mode. To remove the filter, use the no form of this command.
ip pim [vrf vrf-name] rp-announce-filter {group-list access-list | rp-list access-list [group-list access-list]}
no ip pim [vrf vrf-name] rp-announce-filter {group-list access-list | rp-list access-list [group-list access-list]}
Syntax Description
Command Default
All RP announcements are accepted by the RP mapping agent.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
Use the ip pim rp-announce-filter command to filter incoming Auto-RP announcement messages sent from C-RPs to RP mapping agents. This command should only be configured on RP mapping agents.
Auto-RP provides a means to distribute group-to-RP mappings within a multicast network without having to manually configure static RPs on every router. To accomplish this distribution, Auto-RP uses the following mechanisms:
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The ip pim rp-announce filter command allows you to configure policies on an RP mapping agent that define the C-RPs whose RP announcements are to be filtered (ignored) by the mapping agent. You can use this command to configure the mapping agent to filter RP announcement messages from specific or unknown routers by permitting or denying specific C-RPs .You can also filter RP announcement messages from an candidate RP for specific group prefixes, thereby restricting that router to be the C-RP for only the ranges not filtered on the RP mapping agent.
Caution
Caution
Use the rp-list keyword and access-list argument to specify the standard access list that defines the IP addresses of C-RPs whose RP announcements are to be permitted or denied on the RP mapping agent. Use the group-list keyword and access-list argument to specify the standard access list that defines the multicast groups to be permitted or denied from RP announcements sent by C-RPs to the RP mapping agent. RP announcment messages received that match the access list specified for rp-list keyword and access list specified for the group-list keyword are filtered by the RP mapping agent.
If a C-RP list is not specified (using the rp-list keyword and access-list argument), the command will permit all C-RPs. If a group list is not specified (using the group-list keyword and access-list argument), the command will deny all groups.
If no ip pim rp-announce-filter commands are configured, a router enabled to be an RP mapping agent (using the ip pim send-rp-discovery command) will accept all RP announcements for all groups from all C-RPs. Configure one or more ip pim rp-announce-filter commands on RP mapping agents to filter unwanted RP messages.
Examples
The following example shows how to configure the router to accept RP announcements from the C-RPs defined in access list 1 for the group range defined in access list 2:
ip pim rp-announce-filter rp-list 1 group-list 2access-list 1 permit 10.0.0.1access-list 1 permit 10.0.0.2access-list 2 permit 224.0.0.0 15.255.255.255Related Commands
access-list (IP standard)
Defines a standard IP access list.
ip pim send-rp-discovery
Configures the router to be an RP mapping agent.
ip pim rp-candidate
To configure the router to advertise itself to the bootstrap router (BSR) as a Protocol Independent Multicast (PIM) Version 2 candidate rendezvous point (RP), use the ip pim rp-candidate command in global configuration mode. To remove this router as an RP candidate, use the no form of this command.
ip pim [vrf vrf-name] rp-candidate interface-type interface-number [bidir] [group-list access-list] [interval seconds] [priority value]
no ip pim [vrf vrf-name] rp-candidate
Syntax Description
Defaults
The command is disabled.
seconds: 60
priority: 0
Note
Command Modes
Global configuration
Command History
Usage Guidelines
This command causes the router to send a PIM Version 2 message advertising itself as a candidate RP to the BSR. The addresses allowed by the access list, together with the router identified by the type and number, constitute the RP and its range of addresses for which it is responsible.
Use this command only in backbone routers that have good connectivity to all parts of the PIM domain. That is, a stub router that relies on an on-demand dialup link to connect to the rest of the PIM domain is not a good candidate RP.
Use this command with the bidir keyword when you want bidirectional forwarding and you are using the PIM Version 2 BSR mechanism to distribute group-to-RP mappings. Other options are as follows:
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When the interval keyword is specified, the candidate RP advertisement interval is set to a value specified by the seconds argument. The default interval is 60 seconds. Reducing this interval to a time of less than 60 seconds can reduce the time required to fail over to a secondary RP at the expense of generating more PIM Version 2 messages.
Examples
The following example shows how to configure the router to advertise itself as a candidate RP to the BSR in its PIM domain. Standard access list number 4 specifies the group prefix associated with the RP that has the address identified by Ethernet interface 2. That RP is responsible for the groups with the prefix 239.
ip pim rp-candidate ethernet 2 group-list 4access-list 4 permit 239.0.0.0 0.255.255.255Related Commands
ip pim send-rp-announce
To use Auto-RP to configure groups for which the router will act as a rendezvous point (RP), use the ip pim send-rp-announce command in global configuration mode. To unconfigure this router as an RP, use the no form of this command.
ip pim [vrf vrf-name] send-rp-announce {interface-type interface-number | ip-address} scope ttl-value [group-list access-list] [interval seconds] [bidir]
no ip pim [vrf vrf-name] send-rp-announce {interface-type interface-number | ip-address}
Syntax Description
Defaults
Auto-RP is disabled.
seconds: 60Command Modes
Global configuration
Command History
Usage Guidelines
Enter this command on the router that you want to be an RP. When you are using Auto-RP to distribute group-to-RP mappings, this command causes the router to send an Auto-RP announcement message to the well-known group CISCO-RP-ANNOUNCE (224.0.1.39). This message announces the router as a candidate RP for the groups in the range described by the access list.
Use this command with the bidir keyword when you want bidirectional forwarding and you are using Auto-RP to distribute group-to-RP mappings. Other options are as follows:
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Examples
The following example shows how to configure the router to send RP announcements out all Protocol Independent Multicast (PIM)-enabled interfaces for a maximum of 31 hops. The IP address by which the router wants to be identified as RP is the IP address associated with Ethernet interface 0. Access list 5 describes the groups for which this router serves as RP.
ip pim send-rp-announce ethernet0 scope 31 group-list 5access-list 5 permit 224.0.0.0 15.255.255.255Related Commands
ip pim send-rp-discovery
To configure the router to be a rendezvous point (RP) mapping agent, use the ip pim send-rp-discovery command in global configuration mode. To deconfigure the router from functioning as the RP mapping agent, use the no form of this command.
ip pim [vrf vrf-name] send-rp-discovery [interface-type interface-number] scope ttl-value [interval seconds]
no ip pim [vrf vrf-name] send-rp-discovery
Syntax Description
Command Default
The router is not configured to be an RP mapping agent.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the ip pim send-rp-discovery command to configure the router to be an RP mapping agent. An RP mapping agent receives Auto-RP announcement messages, which it stores in its local group-to-RP mapping cache. The RP mapping agent uses the information contained in the Auto-RP announcement messages to elect the RP. The RP mapping agent elects the candidate RP with the highest IP address as the RP for a group range.
The required scope keyword and ttl-value argument are used to specify the TTL value in the IP header of Auto-RP discovery messages.
Note
The optional interval keyword and seconds argument are used to specify the interval at which Auto-RP discovery messages are sent. By default, Auto-RP discovery messages are sent at an interval of 60 seconds or when the RP mapping agent detects changes.
Note
When Auto-RP is used, the following events occur:
1.
2.
3.
4.
5.
Use the show ip pim rp command with the mapping keyword to display all the group-to-RP mappings that the router has learned from Auto-RP.
Examples
The following example shows how to configure a router to be an RP mapping agent. In this example, the RP mapping agent is configured to use loopback 0 as the source address for Auto-RP messages. The Auto-RP discovery messages sent by the RP mapping agent are configured to be sent out at an interval of 50 seconds with a TTL of 20 hops.
ip pim send-rp-discovery loopback 0 scope 20 interval 50Related Commands
show ip pim rp
Displays active RPs that are cached with associated multicast routing entries.
ip pim sparse sg-expiry-timer
To adjust the (S, G) expiry timer interval for Protocol Independent Multicast sparse mode (PIM-SM) (S, G) multicast routes (mroutes), use the ip pim sparse sg-expiry-timer command in global configuration mode. To restore the default setting with respect to this command, use the no form of this command.
ip pim [vrf vrf-name] sparse sg-expiry-timer seconds [sg-list access-list]
no ip pim [vrf vrf-name] sparse sg-expiry-timer
Syntax Description
Command Default
The expiry timer interval for PIM-SM (S, G) mroute entries is set to 180 seconds.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
Use the ip pim sparse sg-expire-timer command to adjust the expiry timer interval for PIM-SM (S, G) mroute entries to a time value greater than the default expiry timer interval of 180 seconds. This command can be used to lock down the shortest-path tree (SPT) for intermittent sources in PIM-SM network environments, such as sources in trading floor environments that sporadically send financial data streams to multicast groups during trading floor hours.
When a source stops sending traffic to a multicast group, the corresponding (S, G) mroute entry eventually times out and the (S, G) entry is removed. When the source resumes sending traffic to the group, the (S, G) entry is rebuilt. During the short time interval before the (S, G) entry is rebuilt, the traffic is forwarded on the (*, G) forwarding entry. There is a small window of time before the (S, G) entry is completely built in which packets may be dropped. The ip pim sparse sg-expiry-timer command can be used to maintain the (S, G) entry so that it will not be removed and the stream will not potentially suffer packet loss.
Note
Examples
The following example shows how to adjust the expiry timer interval to 36000 seconds (10 hours) for PIM-SM (S, G) entries that match the extended access list named test_acl.
ip pim sparse sg-expiry-timer 36000 sg-list test_acl!ip access-list extended test-aclpermit ip any host 234.1.1.1ip pim snooping (global configuration)
To enable Protocol Independent Multicast (PIM) snooping globally, use the ip pim snooping command in global configuration mode. To disable PIM snooping globally, use the no form of this command.
ip pim snooping
no ip pim snooping
Syntax Description
This command has no arguments or keywords.
Defaults
PIM snooping is not enabled.
Command Modes
Global configuration
Command History
Usage Guidelines
PIM snooping is not supported on groups that use the reserved MAC address range, for example, 0100.5e00.00xx, as an alias.
When you disable PIM snooping globally, PIM snooping is disabled on all VLANs.
Examples
This example shows how to enable PIM snooping globally:
ip pim snoopingThis example shows how to disable PIM snooping globally:
no ip pim snoopingRelated Commands
ip pim snooping (interface configuration)
To enable Protocol Independent Multicast (PIM) snooping on an interface, use the ip pim snooping command in interface configuration mode. To disable PIM snooping on an interface, use the no form of this command.
ip pim snooping
no ip pim snooping
Syntax Description
This command has no arguments or keywords.
Defaults
PIM snooping is disabled on an interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
PIM snooping is not supported on groups that use the reserved MAC address range, for example, 0100.5e00.00xx, as an alias.
You must enable PIM snooping globally before enabling PIM snooping on an interface. To enable PIM snooping globally, use the ip pim snooping command in global configuration mode. When you disable PIM snooping globally, PIM snooping is disabled on all VLANs.
You can enable PIM snooping on VLAN interfaces only.
Examples
This example shows how to enable PIM snooping on a VLAN interface:
interface vlan 101ip pim snoopingThis example shows how to disable PIM snooping on a VLAN interface:
interface vlan 101no ip pim snoopingRelated Commands
ip pim snooping (global configuration)
Enables PIM snooping globally.
show ip pim snooping
Displays information about IP PIM snooping.
ip pim snooping dr-flood
To enable flooding of the packets to the designated router, use the ip pim snooping dr-flood command in global configuration mode. To disable the flooding of the packets to the designated router, use the no form of this command.
ip pim snooping dr-flood
no ip pim snooping dr-flood
Syntax Description
This command has no arguments or keywords.
Defaults
The flooding of packets to the designated router is enabled by default.
Command Modes
Global configuration
Command History
Usage Guidelines
PIM snooping is not supported on groups that use the reserved MAC address range, for example, 0100.5e00.00xx, as an alias.
Enter the no ip pim snooping dr-flood command only on switches that have no designated routers attached.
The designated router is programmed automatically in the (S,G) O-list.
Examples
The following example shows how to enable flooding of the packets to the designated router:
ip pim snooping dr-floodThe following example shows how to disable flooding of the packets to the designated router:
no ip pim snooping dr-floodRelated Commands
ip pim snooping suppress sgr-prune
To enable suppression of SGR-prune packets to the designated router, use the ip pim snooping suppress sgr-prune command in global configuration mode. To disable the suppression of the packets to the designated router, use the no form of this command.
ip pim snooping suppress sgr-prune
no ip pim snooping suppress sgr-prune
Syntax Description
This command has no arguments or keywords.
Command Default
The suppression of packets to the designated router is disabled by default.
Command Modes
Global configuration mode
Command History
12.2(18)ZY
This command was introduced.
12.2(18)SXF
This command was introduced.
Usage Guidelines
If a shared tree and SPT diverge in a VLAN on your switch router, and you have PIM snooping configured, then duplicate multicast packets may be delivered in your network. PIM snooping may stop the prune message sent by the receiver from reaching the upstream switch router in the shared tree, which causes more than one upstream switch router to forward the multicast traffic. This situation causes duplicate multicast packets to be delivered to the receivers. The sending of duplicate multicast packets only lasts a couple of seconds because the PIM-ASSERT mechanism is initiated and stops the extraneous flow. However, the cycle repeats itself when the next prune message is sent. To stop this situation from occurring, enter the no ip pim snooping suppress sgr-prune command.
Examples
The following example shows how to enable suppression of the SGR-prune packets to the designated router:
Router(config)# ip pim snooping suppress sgr-pruneRelated Commands
ip pim spt-threshold
To configure when a Protocol Independent Multicast (PIM) leaf router should join the shortest path source tree for the specified group, use the ip pim spt-threshold command in global configuration mode. To restore the default value, use the no form of this command.
ip pim [vrf vrf-name] spt-threshold {kbps | infinity} [group-list access-list]
no ip pim [vrf vrf-name] spt-threshold {kbps | infinity} [group-list access-list]
Syntax Description
Defaults
When this command is not used, the PIM leaf router joins the shortest path tree immediately after the first packet arrives from a new source.
Command Modes
Global configuration
Command History
Usage Guidelines
If a source sends at a rate greater than or equal to traffic rate (the kbps value), a PIM join message is triggered toward the source to construct a source tree.
If the infinity keyword is specified, all sources for the specified group will use the shared tree. Specifying a group list access list indicates the groups to which the threshold applies.
If the traffic rate from the source drops below the threshold traffic rate, the leaf router will switch back to the shared tree and send a prune message toward the source.
Examples
The following example shows how to set a threshold of 4 kbps. If the traffic rate exceeds this threshold, the traffic to a group from a source causes the router to switch to the shortest path tree to that source.
ip pim spt-threshold 4ip pim ssm
To define the Source Specific Multicast (SSM) range of IP multicast addresses, use the ip pim ssm command in global configuration mode. To disable the SSM range, use the no form of this command.
ip pim [vrf vrf-name] ssm {default | range access-list}
no ip pim [vrf vrf-name] ssm {default | range access-list}
Syntax Description
Defaults
The command is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
When an SSM range of IP multicast addresses is defined by the ip pim ssm command, no Multicast Source Discovery Protocol (MSDP) Source-Active (SA) messages will be accepted or originated in the SSM range.
Examples
The following example shows how to configure SSM service for the IP address range defined by access list 4:
access-list 4 permit 224.2.151.141ip pim ssm range 4Related Commands
ip pim state-refresh disable
To disable the processing and forwarding of PIM dense mode state refresh control messages on a Protocol Independent Multicast (PIM) router, use the ip pim state-refresh disable command in global configuration mode. To reenable the processing and forwarding of PIM dense mode state refresh control messages, use the no form of this command.
ip pim [vrf vrf-name] state-refresh disable
no ip pim [vrf vrf-name] state-refresh disable
Syntax Description
vrf
(Optional) Supports the multicast Virtual Private Network (VPN) routing and forwarding (VRF) instance.
vrf-name
(Optional) Name assigned to the VRF.
Defaults
The processing and forwarding of PIM dense mode state refresh control messages is enabled on PIM routers that are running a Cisco IOS software release that supports the PIM dense mode state refresh feature.
Command Modes
Global configuration
Command History
Usage Guidelines
Configuring this command removes PIM dense mode state refresh information from PIM hello messages.
Examples
The following example shows how to disable the periodic forwarding of the PIM dense mode state refresh control message down a source-based IP multicast distribution tree:
ip pim state-refresh disableRelated Commands
ip pim state-refresh origination-interval
To configure the origination of and the interval for PIM dense mode state refresh control messages on a Protocol Independent Multicast (PIM) router, use the ip pim state-refresh origination-interval command in interface configuration mode. To stop the origination of the PIM dense mode state refresh control message, use the no form of this command.
ip pim state-refresh origination-interval [interval]
no ip pim state-refresh origination-interval [interval]
Syntax Description
interval
(Optional) The number of seconds between PIM dense mode state refresh control messages. The default is 60 seconds. The available interval range is from 4 to 100 seconds.
Defaults
PIM dense mode state refresh control message origination is disabled. By default, all PIM routers that are running a Cisco IOS software release that supports PIM dense mode state refresh process and forward PIM dense mode state refresh control messages.
Command Modes
Interface configuration
Command History
Usage Guidelines
Configure this command on the interfaces of the first hop, PIM dense mode routers that are directly connected to sources for PIM-DM multicast groups.
By default, the processing and forwarding of PIM dense mode state refresh control messages is enabled on PIM routers that are running a Cisco IOS software release that supports PIM dense mode state refresh.
Examples
The following example configures the origination of the state refresh control message on Ethernet interface 0 of a PIM dense mode router with an interval of 80 seconds:
interface ethernet 0ip pim state-refresh origination-interval 80Related Commands
