Table Of Contents
clear ip rtp header-compression
frame-relay ip rtp header-compression
frame-relay map ip rtp header-compression
ip dvmrp routehog-notification
ip igmp last-member-query-interval
ip igmp query-max-response-time
ip rtp compression-connections
show frame-relay ip rtp header-compression
show ip rtp header-compression
IP Multicast Routing Commands
This chapter describes the commands used to configure and monitor IP multicast routing. For IP multicast routing configuration information and examples, refer to the "Configuring IP Multicast Routing" chapter of the Cisco IOS IP and IP Routing Configuration Guide.
clear ip cgmp
To clear all group entries from the caches of Catalyst switches, use the clear ip cgmp EXEC command.
clear ip cgmp [type number]
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
This command sends a Cisco Group Management Protocol (CGMP) Leave message with a group address of 0000.0000.0000 and a unicast address of 0000.0000.0000. This message instructs the switches to clear all group entries they have cached.
If an interface type and number are specified, the Leave message is sent only on that interface. Otherwise, it is sent on all CGMP-enabled interfaces.
Examples
The following example clears the CGMP cache:
clear ip cgmpRelated Commands
clear ip dvmrp route
To delete routes from the DVMRP routing table, use the clear ip dvmrp route EXEC command.
clear ip dvmrp route {* | route}
Syntax Description
*
Clears all routes from the DVMRP table.
route
Clears the longest matched route. Can be an IP address, a network number, or an IP DNS name.
Command Modes
EXEC
Command History
Examples
The following example deletes route 10.1.1.1 from the Distance Vector Multicast Routing Protocol (DVMRP) routing table:
clear ip dvmrp route 10.1.1.1clear ip igmp group
To delete entries from the Internet Group Management Protocol (IGMP) cache, use the clear ip igmp group EXEC command.
clear ip igmp group [group-name | group-address | type number]
Syntax Description
Defaults
When the command is used with no arguments, all entries are deleted from the IGMP cache.
Command Modes
EXEC
Command History
Usage Guidelines
The IGMP cache contains a list of the multicast groups of which hosts on the directly connected LAN are members. If the router has joined a group, it is also listed in the cache.
To delete all entries from the IGMP cache, specify the clear ip igmp group command with no arguments.
Examples
The following example clears entries for the multicast group 224.0.255.1 from the IGMP cache:
clear ip igmp group 224.0.255.1Related Commands
clear ip mroute
To delete entries from the IP multicast routing table, use the clear ip mroute EXEC command.
clear ip mroute {* | group [source]}
Syntax Description
Command Modes
EXEC
Command History
Examples
The following example deletes all entries from the IP multicast routing table:
clear ip mroute *The following example deletes from the IP multicast routing table all sources on the 10.3.0.0 subnet that are transmitting to the multicast group 224.2.205.42. Note that this example deletes all sources on network 10.3, not individual sources.
clear ip mroute 224.2.205.42 10.3.0.0Related Commands
ip host
Defines a static host name-to-address mapping in the host cache.
Displays the contents of the IP multicast routing table.
clear ip pim auto-rp
To delete entries from the Auto-RP cache, use the clear pim auto-rp EXEC command.
clear ip pim auto-rp rp-address
Syntax Description
rp-address
Clears only the entries related to the RP at this address. If this argument is omitted, the entire Auto-RP cache is cleared.
Command Modes
EXEC
Command History
Examples
The following example deletes all entries from the Auto-RP cache:
clear ip pim auto-rpclear ip rtp header-compression
To clear Real-Time Transport Protocol (RTP) header compression structures and statistics, use the clear ip rtp header-compression EXEC command.
clear ip rtp header-compression [type number]
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
If this command is used without an interface type and number, it clears all RTP header compression structures and statistics.
Examples
The following example clears RTP header compression structures and statistics for serial interface 0:
clear ip rtp header-compression serial 0Related Commands
clear ip sdr
To delete a Session Directory Protocol (sdr) cache entry or the entire sdr cache, use the clear ip sdr EXEC command.
clear ip sdr [group-address | "session-name"]
Syntax Description
group-address
(Optional) Deletes all sessions associated with the IP group address.
"session-name"
(Optional) Deletes only the sdr cache entry with the specified name.
Command Modes
EXEC
Command History
Usage Guidelines
If no arguments or keywords are used with this command, the system deletes the entire sdr cache.
Examples
The following example clears the sdr cache:
clear ip sdrRelated Commands
Limits how long a sdr cache entry stays active in the cache.
Enables the Cisco IOS software to listen to session directory advertisements.
Displays the session directory cache.
frame-relay ip rtp header-compression
To enable Real-Time Transport Protocol (RTP) header compression for all Frame Relay maps on a physical interface, use the frame-relay ip rtp header-compression interface configuration command. To disable the compression, use the no form of this command.
frame-relay ip rtp header-compression [active | passive]
no frame-relay ip rtp header-compression [active | passive]
Syntax Description
active
(Optional) Compresses all outgoing RTP packets. This is the default.
passive
(Optional) Compresses the outgoing RTP/UDP/IP header only if an incoming packet had a compressed header.
Defaults
Disabled.
If the command is configured, active is the default keyword.
Command Modes
Interface configuration
Command History
Usage Guidelines
When this command is used on the physical interface, all the interface maps inherit the command; that is, all maps will perform IP/UDP/RTP header compression.
Examples
The following example enables RTP header compression for all Frame Relay maps on a physical interface:
frame-relay ip rtp header-compressionRelated Commands
frame-relay map ip compress
To enable both Real-Time Transport Protocol (RTP) and TCP header compression on a link, use the frame-relay map ip compress interface configuration command. To disable both RTP and TCP header compression, use the no form of this command.
frame-relay map ip ip-address dlci [broadcast] compress
no frame-relay map ip ip-address dlci [broadcast] compress
Syntax Description
ip-address
IP address of the destination or next hop.
dlci
DLCI number.
broadcast
(Optional) Forwards broadcasts to the specified IP address.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Examples
The following example enables both RTP and TCP header compression on serial interface 1:
interface serial 1encapsulation frame-relayip address 131.108.175.110 255.255.255.0frame-relay map ip 131.108.175.220 180 compressRelated Commands
frame-relay map ip rtp header-compression
To enable Real-Time Transport Protocol (RTP) header compression per data-link connection identifier (DLCI), use the frame-relay map ip rtp header-compression interface configuration command. To disable the compression, use the no form of this command.
frame-relay map ip ip-address dlci rtp header-compression [active | passive]
no frame-relay map ip ip-address dlci rtp header-compression [active | passive]
Syntax Description
Defaults
Disabled.
If the command is configured, active is the default keyword.
Command Modes
Interface configuration
Command History
Usage Guidelines
When this command is configured, the specified maps inherit RTP header compression. You can have multiple Frame Relay maps, with and without RTP header compression.
Examples
The following example enables RTP header compression on serial interface 1:
interface serial 1encapsulation frame-relayip address 131.108.175.110 255.255.255.0frame-relay map ip 131.108.175.220 180 rtp header-compressionRelated Commands
ip cgmp
To enable Cisco Group Management Protocol (CGMP) on an interface of a router connected to a Catalyst 5000 switch, use the ip cgmp interface configuration command. To disable CGMP routing, use the no form of this command.
ip cgmp [proxy]
no ip cgmp
Syntax Description
Defaults
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 router's MAC address on the interface for group 0000.0000.0000 (all groups). CGMP can run on an interface only if PIM is configured on the same interface.
A Cisco router will send CGMP Join messages in response to receiving IGMP reports from IGMP-capable members. Only the CGMP querier Cisco router sends these CGMP Join messages on behalf of hosts.
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 non-CGMP-capable router's MAC address and a group address of 0000.0000.0000.
Initially supported is 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 with 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, it is recommended that all of them 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 interface configuration command. To disable this filter, use the no form of this command.
ip dvmrp accept-filter access-list-number [distance | neighbor-list access-list-number]
no ip dvmrp accept-filter access-list-number [distance | neighbor-list access-list-number]
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 distance.
The distance 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. This means that they always take precedence over unicast routing table routes. If you have two paths to a source, one through unicast routing (using 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. For example, if the unicast routing protocol is Enhanced IGRP, which has a default administrative distance of 90, you could define and apply the following access list so the RPF interface used to accept multicast packets will be through the Enhanced IGRP/PIM path:
ip dvmrp accept-filter 1 100access-list 1 permit 0.0.0.0 255.255.255.255Examples
The following example applies access list 57 to the interface and sets a distance of 4:
access-list 57 permit 131.108.0.0 0.0.255.255access-list 57 permit 198.92.37.0 0.0.0.255access-list 57 deny 0.0.0.0 255.255.255.255ip dvmrp accept-filter 57 4Related Commands
ip dvmrp auto-summary
To enable Distance Vector Multicast Routing Protocol (DVMRP) auto summarization if it was disabled, use the ip dvmrp auto-summary interface configuration command. 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
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
DVMRP auto summarization occurs when a unicast subnet route is collapsed into a classful network number route. This 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.
You might want to 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 auto-summarization.
Examples
The following example disables DVMRP auto summarization:
no ip dvmrp auto-summaryRelated Commands
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 interface configuration command. 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
Other routes more specific than 0.0.0.0 can also be advertised.
only
No DVMRP routes other than 0.0.0.0 are advertised.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
This command should only be used when the router is a neighbor to mrouted version 3.6 machines. 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
To configure the metric associated with a set of destinations for Distance Vector Multicast Routing Protocol (DVMRP) reports, use the appropriate form of the ip dvmrp metric interface configuration command. To disable this function, use the appropriate no form of this command.
ip dvmrp metric metric [list access-list-number] [mbgp]
no ip dvmrp metric metric [list access-list-number] [mbgp]
ip dvmrp metric metric [list access-list-number] [[protocol process-id] | dvmrp]
no ip dvmrp metric metric [list access-list-number] [[protocol process-id] | dvmrp]
ip dvmrp metric metric route-map map-name [mbgp]
no ip dvmrp metric metric route-map map-name [mbgp]
Syntax Description
Defaults
No metric 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.
12.1
The 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 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 198.92.35.0 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 198.92.35.0 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.
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 interface configuration command. 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.
The default for in is 1.
The default for out is 0.
Command 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 interface configuration command. 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 is 100 milliseconds
burst is 2 packets
Command 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 6 packets are built, 3 packets will be sent, then a delay of 200 milliseconds occurs, then the next 3 packets are 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 interface configuration command. 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
Disabled
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 non-pruning routers multiple hops away (downstream toward potential receivers) that are not rejected, then a non-pruning 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 global configuration command. 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 one-minute interval before a syslog message is issued, warning that there might be a route surge occurring. The warning is typically used to detect quickly when people have misconfigured their routers to inject a large number of routes into the 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 global configuration command. To configure no limit, use the no form of this command.
ip dvmrp route-limit count
no ip dvmrp route-limit
Syntax Description
Defaults
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, or an interface configured to run the ip dvmrp unicast-routingcommand.
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 summary-address
To configure a DVMRP summary address to be advertised out the interface, use the ip dvmrp summary-address interface configuration command. To remove the summary address, use the no form of this command.
ip dvmrp summary-address address mask [metric value]
no ip dvmrp summary-address address mask [metric value]
Syntax Description
Defaults
metric value is 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 address 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 171.69.0.0 to be advertised out the interface:
ip dvmrp summary-address 171.69.0.0 255.255.0.0 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 interface configuration command. 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
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 PIM is running, these routes may get preference over routes in the unicast routing table. This allows PIM to run on the MBONE topology when it is different from the unicast topology.
DVMRP unicast routing can run on all interfaces, including 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/DVMRP multicast routing interaction.
Examples
The following example enables DVMRP unicast routing:
ip dvmrp unicast-routingRelated Commands
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 interface configuration command. To disable groups on an interface, use the no form of this command.
ip igmp access-group access-list-number version
no ip igmp access-group access-list-number version
Syntax Description
access-list-number
Number of a standard IP access list. This can be a number from 1 to 99.
version
Changes IGMP version. Default is version 2.
Defaults
All groups are allowed on an interface.
Command Modes
Interface configuration
Command History
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 1Related Commands