Configuring a Share-Group
Context
An MD is a group of VPN instances that can transmit and receive multicast packets between PEs. Different VPN instances belong to different MDs. An MD serves a specific VPN. All private multicast data transmitted in the VPN is transmitted in the MD. Share-MDT is a basic concept of multicast VPN based on multicast domain (MD). A Share-MDT is a multicast distribution tree (MDT) established among all PE devices on a VPN. PE devices encapsulate VPN multicast packets into public network multicast data packets using the Share-Group address as the group address. These packets are then forwarded along the Share-MDT. The Share-MDT exists on the backbone network regardless of whether multicast services are running on the backbone network or VPNs.
Perform the following steps on a PE.
One Share-Group address cannot be configured for different VPN instances on a PE.
In MD VPN, the value range of a Share-Group address is the same as that of an Any-Source Multicast (ASM) group address range.
Procedure
- Run system-view
The system view is displayed.
- Run ip vpn-instance vpn-instance-name
The VPN instance view is displayed.
- (Optional) Run ipv4-family
The IPv4 address family is enabled for the VPN instance, and the VPN instance IPv4 address family view is displayed.
By default, the VPN instance IPv4 address family is enabled after a router distinguisher (RD) and a VPN target are configured for a VPN instance.
- Run multicast-domain share-group group-address binding mtunnel number
A Share-Group is configured. The system automatically creates a multicast tunnel interface (MTI), binds the Share-Group to the MTI, and binds the MTI to the VPN instance.
A VPN instance must be configured with the same Share-Group address on all PE devices. Each Share-Group address identifies a Share-MDT. If a VPN instance has different Share-Group addresses on PE devices, the Share-MDT cannot be established on the PE devices bound to the VPN instance.
After an MTI is created, the system automatically configures Protocol Independent Multicast (PIM) for the MTI. Manual configuration is not required. By default, PIM Sparse Mode (PIM-SM) is enabled for an MTI. If another interface is bound to the VPN instance, the PIM protocol enabled on the MTI automatically synchronizes with that configured on the interface.