HPE 5820X Series, Configuration Manual

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Figure 83 MD VPN inter-AS option B
To implement MD VPN inter-AS option B, only one MD needs to be established for the two ASs. VPN
multicast data is transmitted between different ASs on the public network within this MD.
NOTE:
Only PIM-SSM mode is supported on the public network of MD VPN inter-AS option B.
The establishment of the MDT on the public network is as follows:
1.
PE 1 originates a PIM join message to join the SPT rooted at PE 2. In the join message, the
upstream neighbor address is the IP address of PE 2 (the BGP connector). The RPF vector
attribute is the IP address of PE 3. PE 1 encapsulates the join message as a public network
packet and forwards it through the MTI.
2.
P 1 determines that the RPF vector is not an IP address of its own. It looks up the routing table
for a route to PE 3, and forwards the packet to PE 3.
3.
PE 3 removes the RPF vector because the RPF vector is its own IP address. It fails to find a
BGP MDT route to PE 2, so it encapsulates a new RPF vector (IP address of PE 4) in the packet
and forwards it to PE 4.
4.
PE 4 removes the RPF vector because the RPF vector is its own IP address. It has a local route
to PE 2, so it forwards the packet to P 2, which is the next hop of the route to PE 2.
5.
P 2 sends the packet to PE 2.
6.
PE 2 receives the packet on the MTI and decapsulates the packet. The receiving interface is the
RPF interface of the RPF route back to PE 1 for the join message, and the join message passes
the RPF check. The SPT from PE 1 to PE 2 is established.
When PE 1 joins the SPT rooted at PE 1, PE 2 also initiates a join process to the SPT rooted at PE 1.
A MDT is established when the two SPTs are finished.
Multicast VPN configuration task list
Task Remarks
Configuring MD-VPN
Enabling IP multicast routing in a VPN instance Required.
Configuring a share-group and an MTI binding Required.
Configuring MDT switchover parameters Optional.
Configuring the RPF vector feature Optional.
Enabling data-group reuse logging Optional.
Configuring BGP MDT Configuring BGP MDT peers or peer groups Required.