SPB-PIM Gateway Node

The SPB-PIM Gateway Node (Gateway) has the following components:
  • Gateway Selection Agent

  • SPB-PIM Gateway interface

Gateway Selection Agent

The Gateway Selection Agent (Agent) resides in the Gateway BEB Node in the SPB network. The Gateway BEB has connections into the foreign network over SPB-PIM Gateway Interfaces. The Agent receives foreign network source information from the Controller BEB or the Controller BCB Node. The source information consists of the following components:
  • Sender IP address (S)

  • Group IP address (G)

  • VSN identifier (ISID)

  • Gateway assigned to the stream

The Agent interacts with SPB-PIM Gateway interface and creates the multicast path. The Agent receives foreign source information from the Controller and creates a foreign source address (SA) cache after validating the reachability to S. The Agent interacts with the SPB-PIM Gateway interface to validate that the next-hop ip address toward the source is a valid PIM adjacency. The foreign SA cache includes the following components:
  • Source IP address (information received from the Gateway Controller)

  • Group IP address (information received from the Gateway Controller)

  • Ingress port (The port through which S is accessible)

  • Upstream IP address (The next-hop IP address, which is also the PIM neighbor across the SPB-PIM Gateway interface which is used to reach S as indicated by the unicast routing entry)

  • Ingress VLAN ID

If multiple next-hops are available, then the first valid PIM neighbor next-hop is used for the upstream.
Note

Note

If the Agent receives the same source information from multiple Controllers, then the Agent takes action only for the information received from the preferred Controller. The Controller with the lowest system ID is the preferred Controller.

SPB-PIM Gateway interface

The SPB-PIM Gateway interface provides inter-domain multicast services. The SPB-PIM Gateway interface connects senders and receivers of multicast streams across a PIM Domain and a SPB network boundary over a Gateway interface. The SPB-PIM Gateway interface provides the following functionality:
  • PIM HELLO exchanges

  • Issuing Joins and Leaves

  • Process received Joins and Leaves

  • Implements the Gateway assignment table by acting as the Ingress BEB for streams for which the SPB-PIM Gateway interface is the selected Gateway

  • Enforces the Gateway assignment table and does not forward streams for which the SPB-PIM Gateway interface is not the selected Gateway

  • Forwards local and remote SPB streams to satisfy stream requests from neighboring multicast domains

  • SPB-PIM Gateway Interfaces supports both SM and SSM multicast group range joins and prunes. *G joins are only supported in SM group range.

The PIM Gateway interface resides in the SPB-PIM Gateway Node (Gateway). The SPB-PIM Gateway interface connects to a PIM router in a PIM network or to another Gateway BEB in an SPB network. Local hosts (IGMP member hosts and multicast data source hosts) are not supported on SPB-PIM Gateway interfaces, only PIM Routers or another SPB BEB with SPB-PIM Gateway interface configured. Multicast data from local source hosts and IGMP reports from local hosts are dropped. An SPB Node must be configured as a SPB-PIM Gateway Node if the SPB Node is connected to a foreign PIM network or a foreign SPB network. A single Gateway Node can have multiple SPB-PIM Gateway interfaces. The SPB-PIM Gateway interface can be a VLAN or a brouter port, can reside on an MLT and is fully virtualized. The SPB-PIM Gateway interface is a translation mechanism between the PIM protocol and SPB TLVs.
Note

Note

  • Only PIM protocol messages are communicated over the SPB-PIM Gateway interface

  • Only SPB TLVs are communicated over Fabric Connect over SPB

  • The SPB-PIM Gateway interface is the only component that handles the translation mechanism

The SPB-PIM Gateway interface communicates with the PIM router through the standard PIM protocol messaging HELLO, JOIN, and PRUNE. The SPB-PIM Gateway interface then forms a normal PIM adjacency with the PIM router or another SPB Gateway Node. The SPB-PIM Gateway Interface processes received SG joins and prunes, *G joins and prunes, and SG-RPT joins and prunes. The SPB-PIM Gateway interface transmits SG joins and prunes, but never *G joins.The SPB-PIM Gateway Interface does not have RP capabilities, and therefore has no need for group-to-RP mapping configurations. A *G JOIN received on a SPB-PIM Gateway Interface is accepted if the destination IP is the IP address of the interface or of a neighbor on the interface if the neighbor is learned on another port in the interface. However, the RP address within the *G JOIN message is ignored by the SPB-PIM Gateway Interface.