How to transport the multicast traffic without any PIM or IGMP join messages received ?
相對於大家都很熟悉的指令 - 'ip igmp join-group'，這邊我要跟各位介紹一個不常使用到的指令 - 'ip igmp static-group'
ip igmp static-group
To configure static group membership entries on an interface, use the ip igmp static-group command in interface configuration mode. To delete static group membership entries, use the no form of this command.
Usage Guidelines
Use the ip igmp static-group command to configure static group membership entries on an interface. When you configure the ip igmp static-group command, packets to the group are fast-switched out the interface, provided that packets were received on the correct reverse path forwarding (RPF) interface. Once configured, static group membership entries are added to the IGMP cache and mroute table.
Configuring the ip igmp static-group command is unlike configuring the ip igmp join-group command, which allows the router to join the multicast group. This configuration of the ip igmp static-group command would cause the upstream routers to maintain the multicast routing table information for that group, which would ensure that all the paths to that multicast group are active.
If you configure the ip igmp join-group command for the same group address as the ip igmp static-group command, the ip igmp join-group command takes precedence, and the group behaves like a locally joined group.
Use the ip igmp static-group command with the ssm-map keyword to configure static traffic forwarding with SSM mapping on the last hop router. Static traffic forwarding can be used in conjunction with SSM mapping to statically forward SSM traffic for certain groups. When static traffic forwarding with SSM mapping is configured, the last hop router uses Domain Name System (DNS)-based SSM mapping to determine the sources associated with a group. The resulting (S, G) channels are then statically forwarded.
Use the ip igmp static-group class-map command with the class-map keyword and class-map-name argument to attach an IGMP static group class map to an interface. Once attached, all groups entries that are defined in the class map become static members on the interface and are added to the IGMP cache and to the mroute table.
Examples
The following example shows how to configure group address 239.100.100.101 on Ethernet interface 0:
ip igmp static-group
To configure static group membership entries on an interface, use the ip igmp static-group command in interface configuration mode. To delete static group membership entries, use the no form of this command.
ip igmp static-group {* | group-address [source {source-address | ssm-map}] | class-map class-map-name}no ip igmp static-group {* | group-address [source {source-address | ssm-map}] | class-map class-map-name}Usage Guidelines
Use the ip igmp static-group command to configure static group membership entries on an interface. When you configure the ip igmp static-group command, packets to the group are fast-switched out the interface, provided that packets were received on the correct reverse path forwarding (RPF) interface. Once configured, static group membership entries are added to the IGMP cache and mroute table.
Configuring the ip igmp static-group command is unlike configuring the ip igmp join-group command, which allows the router to join the multicast group. This configuration of the ip igmp static-group command would cause the upstream routers to maintain the multicast routing table information for that group, which would ensure that all the paths to that multicast group are active.
If you configure the ip igmp join-group command for the same group address as the ip igmp static-group command, the ip igmp join-group command takes precedence, and the group behaves like a locally joined group.
Use the ip igmp static-group command with the ssm-map keyword to configure static traffic forwarding with SSM mapping on the last hop router. Static traffic forwarding can be used in conjunction with SSM mapping to statically forward SSM traffic for certain groups. When static traffic forwarding with SSM mapping is configured, the last hop router uses Domain Name System (DNS)-based SSM mapping to determine the sources associated with a group. The resulting (S, G) channels are then statically forwarded.
Use the ip igmp static-group class-map command with the class-map keyword and class-map-name argument to attach an IGMP static group class map to an interface. Once attached, all groups entries that are defined in the class map become static members on the interface and are added to the IGMP cache and to the mroute table.
Examples
The following example shows how to configure group address 239.100.100.101 on Ethernet interface 0:
interface ethernet 0
ip igmp static-group 239.100.100.101
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