This feature enables the use of a P2MP LSP as the default tree for forwarding Broadcast, Unicast unknown, and Multicast (BUM) packets of a VPLS or B-VPLS instance. The P2MP LSP is referred to in this case as the Inclusive Provider Multicast Service Interface (I-PMSI).
When enabled, this feature relies on BGP Auto-Discovery (BGP-AD) or BGP-VPLS to discover the PE nodes participating in a specified VPLS/B-VPLS instance. The BGP route contains the information required to signal both the point-to-point (P2P) PWs used for forwarding unicast known Ethernet frames and the RSVP P2MP LSP used to forward the BUM frames. The root node signals the P2MP LSP based on an LSP template associated with the I-PMSI at configuration time. The leaf node automatically joins the P2MP LSP that matches the I-PMSI tunnel information discovered via BGP.
If IGMP or PIM snooping are configured on the VPLS instance, multicast packets matching an L2 multicast Forwarding Information Base (FIB) record are also forwarded over the P2MP LSP.
The user enables the use of an RSVP P2MP LSP as the I-PMSI for forwarding Ethernet BUM and IP multicast packets in a VPLS/B-VPLS instance using the following context:
config>service>vpls [b-vpls]>provider-tunnel>inclusive>rsvp>lsp-template p2mp-lsp-template-name
The user enables the use of an LDP P2MP LSP as the I-PMSI for forwarding Ethernet BUM and IP multicast packets in a VPLS instance using the following context:
config>service>vpls [b-vpls]>provider-tunnel>inclusive>mldp
After the user performs a no shutdown under the context of the inclusive node and the expiration of a delay timer, BUM packets are forwarded over an automatically signaled mLDP P2MP LSP or over an automatically signaled instance of the RSVP P2MP LSP specified in the LSP template.
The user can specify that the node is both root and leaf in the VPLS instance:
config>service>vpls [b-vpls]>provider-tunnel>inclusive>root-and-leaf
The root-and-leaf command is required; otherwise, this node behaves as a leaf-only node by default. When the node is leaf only for the I-PMSI of type P2MP RSVP LSP, no PMSI Tunnel Attribute is included in BGP-AD route update messages and, therefore, no RSVP P2MP LSP is signaled, but the node can join an RSVP P2MP LSP rooted at other PE nodes participating in this VPLS/B-VPLS service. The user must still configure an LSP template even if the node is a leaf only. For the I-PMSI of type mLDP, the leaf-only node joins I-PMSI rooted at other nodes it discovered but does not include a PMSI Tunnel Attribute in BGP route update messages. This way, a leaf-only node forwards packets to other nodes in the VPLS/B-VPLS using the point-to-point spoke-SDPs.
BGP-AD (or BGP-VPLS) must have been enabled in this VPLS/B-VPLS instance or the execution of the no shutdown command under the context of the inclusive node is failed and the I-PMSI does not come up.
Any change to the parameters of the I-PMSI, such as disabling the P2MP LSP type or changing the LSP template, requires that the inclusive node be first shut down. The LSP template is configured in MPLS.
If the P2MP LSP instance goes down, VPLS/B-VPLS immediately reverts the forwarding of BUM packets to the P2P PWs. However, the user can restore at any time the forwarding of BUM packets over the P2P PWs by performing a shutdown under the context of the inclusive node.
This feature is supported with VPLS, H-VPLS, B-VPLS, and BGP-VPLS. It is not supported with I-VPLS and R-VPLS.