Multicast
The multicast commands are used to set interface-specific options such as time-to-live (TTL) thresholds and administratively scoped boundaries.
clear ip mroute
Name
clear ip mroute - clears routes in the multicast routing table
Syntax
clear ip mroute gr_address? sr_address?
Mode
User Execution
Parameters
gr_address - optionally specify a valid IPv4 multicast group address that you want removed from the multicast routing table
sr_address - optionally specify a valid IPv4 multicast source address that you want removed from the multicast routing table
Description
Use the clear ip mroute command to remove routes from the multicast routing table. If this command is issued without arguments, then all group and source information will be cleared. Similarly, you can specify to clear a specific group and/or source multicast address.
Command History
NGC 2.2 - This command was introduced.
Examples
The following example clears group/source 226.1.1.1/192.168.0.1 from the multicast routing table.
> clear ip mroute 226.1.1.1 192.168.0.1
ip multicast boundary
Name
ip multicast boundary - specifies an administratively scoped boundary for a single multicast group on the associated interfaces.
Syntax
ip multicast boundary group group-address masklen length
no ip multicast boundary group group-address masklen length
Mode
Interface Configuration
Parameters
group group-address - specify a valid IPv4 address to denote the group address
masklen length - the length of the mask associated with the group prefix, specified as an integer
Description
ip multicast boundary is used to configure administratively scoped group boundaries on the indicated interface(s).
Default
The ip multicast boundary command is not explicitly configured by default.
Command History
NGC 2.2 - This command was introduced.
Examples
In the following example, an administratively scoped boundary for multicast group 224.5.5.5 is configured.
(config-if)# ip multicast boundary group 224.5.5.5
masklen 24
ip multicast ttl-threshold
Name
ip multicast ttl-threshold - specifies the minimum time-to-live that a multicast data packet can have and still be forwarded over the associated interface
Syntax
ip multicast ttl-threshold ttl
no ip multicast ttl-threshold [ ttl ]?
Mode
Interface Configuration
Parameters
ttl - an integer from 0 to 255, inclusive
Description
The ip multicast ttl-threshold command specifies the minimum time-to-live plus1 that a multicast data packet can have and still be forwarded over the associated interface. A value of 0 indicates that no multicast data packets should be forwarded over the associated interface(s).
Default
If ip multicast ttl-threshold is not configured, it is the same as if the user had specified the following:
(config-if)# ip multicast ttl-threshold 0
Command History
NGC 2.2 - This command was introduced.
Examples
The following example configures a threshold of 20 on interface fxp1.
(config)# interface fxp1
(config-if)# ip multicast ttl-threshold 20
show ip mroute
Name
show ip mroute - displays the contents of the Multicast Routing Table
Syntax
show ip mroute
Mode
User Execution
Parameters
none
Description
The output of the show ip mroute query displays the content of the Multicast routing table.
Command History
NGC 2.2 - This command was introduced.
Examples
The following example shows a response to the show ip mroute query.
> show ip mroute
IP Multicasting Routing Table
(*, 224.1.1.1), uptime 0:01:20
Incoming interface: fxp0, RPF neighbor 10.2.11.31
Outgoing interface list:
fxp1
(192.168.101.100, 224.2.2.2), uptime 0:01:20
Incoming interface: fxp1, RPF neighbor 10.2.12.32
Outgoing interface list:
fxp1
Field Descriptions
The following table describes the fields that appear in the Multicast MRT Query.
Table 11‑1 Multicast MRT Query Fields
Field
|
Description
|
(*, 224.1.1.1), (192.168.101.100, 224.2.2.2)
|
The entries in the IP multicast routing table.
|
Uptime
|
The length of time that the (*,G) or (S,G) entry has been created in hours:minutes:seconds.
|
Incoming interface
|
The expected interface for a multicast packet from the source.
|
RPF neighbor
|
The IP address of the upstream router to the source.
|
Outgoing interface list
|
The interfaces through which packets will be forwarded.
|
show ip multicast boundary
Name
show ip multicast boundary - displays all boundaries within all interfaces
Syntax
show ip multicast boundary
Mode
User Execution
Parameters
none
Description
Use the show ip multicast boundary query to obtain summarized information for all boundaries within all interfaces.
Command History
NGC 2.2 - This command was introduced.
Examples
The following example shows a response to the show ip multicast boundary query.
> show ip multicast boundary
[1]fxp0, 224.5.5.0/24
[2]fxp0, 224.5.10.0/24
[3]fxp1, 239.5.0.0/16
show ip multicast ttl-threshold
Name
show ip multicast ttl-threshold - displays information about the multicast TTL threshold
Syntax
show ip multicast ttl-threshold
Mode
User Execution
Parameters
none
Description
The output of the show ip multicast ttl-threshold query displays information about the multicast TTL threshold.
Command History
NGC 2.2 - This command was introduced.
Examples
The following example shows the output of a show ip multicast ttl-threshold query.
> show ip multicast ttl-threshold
fxp0, 1
fxp2, 5
Field Descriptions
The following table describes the fields that appear in the Multicast TTL Threshold Query.
Table 11‑1 Multicast TTL Threshold Query Fields
Field
|
Description
|
fxp0, 1 and fxp1, 5
|
Shows the ttl-threshold value for each interface.
|
|
