HP MSR3024 TAA-compliant AC Router : R0106-HP MSR Router Series IP Multicast Command Reference(V7) : Page 99

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Syntax

display interface [ register-tunnel [ interface-number ] ] [ brief [ description | down ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

register-tunnel: Displays information about the register-tunnel interface. If you do not specify this

keyword, the command displays information about all interfaces on the device.

interface-number: Specifies a register-tunnel interface by its number. The device has only one

register-tunnel interface, and the value for this argument is fixed at 0. The command with the

register-tunnel keyword displays information about Register-Tunnel 0 with or without this argument.

brief: Displays brief information. If you do not specify this keyword, the command displays detailed

information.

description: Displays the full interface description. If you do not specify this keyword, only the first 27

characters of the interface description are displayed.

down: Displays information about the interfaces in down state and the reasons why the interfaces are

down. If you do not specify this keyword, the command displays information about interfaces in all states.

Usage guidelines

The register-tunnel interface is a virtual interface that is automatically created by the system. You cannot

configure on it or delete it, but you can display the interface information by using this command. The

physical state and link state of the register-tunnel interface are always down.

In the initial stage of multicast source registration, the register-tunnel interface is used to establish a

channel between the source-side DR and the RP to transmit multicast register messages. The process of

initial source registration is as follows:

1. After the source-side DR receives the first multicast data from the source, the DR encapsulates the

multicast data into a register message and forwards it to the RP through the register-tunnel

interface.

2. The register message reaches RP on the register-tunnel interface on the RP. The RP decapsulates the

register message and forwards the multicast data to the receiver hosts. At the same time, the RP

learns the IP address of the multicast source.

3. The RP sends a join message toward the multicast source to build an SPT.

4. After the SPT is built, the multicast data travels to the RP along the SPT rather than through the