The multicast-domain switch-group-pool command specifies the conditions for the switchover from the Share-MDT to Switch-MDT and configures the Switch-Group-Pool in a specified VPN instance.
The undo multicast-domain switch-group-pool command restores the default configuration.
By default, the Switch-Group-Pool is not specified, and the switchover to the Switch-MDT is not performed.
multicast-domain switch-group-pool switch-group-pool { network-mask | network-mask-length } [ threshold threshold-value | acl advanced-acl-number ] *
undo multicast-domain switch-group-pool
| Parameter | Description | Value |
|---|---|---|
| switch-group-pool | Specifies the start address of the Switch-Group-Pool. | The value is in dotted decimal notation and ranges from 224.0.1.0 to 239.255.255.255. |
| network-mask | Specifies the mask of a Switch-Group-Pool address. | The value is in dotted decimal notation and ranges from 255.255.255.0 to 255.255.255.255. |
| network-mask-length | Specifies the mask length of a Switch-Group-Pool address. | The value is an integer that ranges from 24 to 32; that is, the range of the group address in the Switch-MDT Switch-Group-Pool is from 0 to 255. |
| threshold threshold-value | Specifies the switchover threshold. | The value is an integer that ranges from 0 to 4194304, in kbit/s. By default, it is 0. |
| acl advanced-acl-number | Specifies the (S, G) entry which the Switch-Group-Pool takes effect on. advanced-acl-number indicates the advanced ACL number. If the ACL is not specified, the Switch-Group-Pool takes effect on all (S, G) entries. | The value is an integer that ranges from 3000 to 3999. |
Usage Scenario
Between the PE connected to the VPN receivers and the PE connected to the VPN multicast source, a special Switch-MDT is set up for the high-speed VPN multicast data packets flowing into the public network. The multicast data flow can be switched from the Share-MDT to the Switch-MDT. Therefore, on-demand multicast can be realized. This prevents data from be flooded in the public network when the Share-MDT is used to transmit VPN multicast data packets.
Prerequisites
A Share-Group has been configured using the multicast-domain share-group binding command.
Follow-up Procedure
In some cases, the forwarding rate of VPN multicast data packets fluctuates above and below the switchover threshold. Configure a delay for the switchover from the Share-MDT to Switch-MDT using the multicast-domain switch-delay command. If the rate remains higher than the switchover threshold throughout the duration of the Switch-Delay timer, the transmission path of data packets is switched to the Switch-MDT; otherwise, the packets are still forwarded along the Share-MDT.
Precautions
On a PE, the address ranges defined by the Switch-Group-Pool cannot overlap for VPN instances.
From the time when data forwarding rate changes to the time when the system starts the switch-delay timer, there is a delay of 1 to 30 seconds because of necessary traffic calculation and protocol processing. In actual switchover, the delay is longer than the switch-delay period by 1 to 30 seconds.
# Configure the Switch-Group-Pool of VPN instance named mytest to range from 225.2.2.1 to 225.2.2.15.
<HUAWEI> system-view [HUAWEI] ip vpn-instance mytest [HUAWEI-vpn-instance-mytest] route-distinguisher 11:11 [HUAWEI-vpn-instance-mytest-af-ipv4] multicast routing-enable [HUAWEI-vpn-instance-mytest-af-ipv4] multicast-domain share-group 224.1.1.1 binding mtunnel 0 [HUAWEI-vpn-instance-mytest-af-ipv4] multicast-domain switch-group-pool 225.2.2.1 28