Abstract: Techniques are described for selecting an alternate path for end-to-end service data traffic that traverses multi-homed routers that provide the service to customer networks. For example, as described herein, a router that is a member of a first multi-homing set connected to a layer two (L2) network with one of a plurality of first access links. The router advertises a status of one of the first access links to a second multi-homing set connected to the first multi-homing set with one or more core links. A core link database stores advertised status information for access links of the first and second multi-homing set. Upon a link failure, a path selector selects a core link to transport service data traffic and directs a switch module to switch to active a status a first access links that connects to a router in the first multi-homing set connected to the selected core link.

Abstract: In general, techniques are described for performing scalable layer two (L2) learning in computer networks. A network device that includes interfaces and a control unit may implement these techniques. The control unit stores a L2 learning table having entries that are each associated with a service tag identifying a service virtual local area network. In response to receiving a packet that includes a service tag, the interfaces access the L2 learning table using the service tag to determine whether any of the entries of the L2 learning table are associated with the service tag. When none of the entries are associated with the service tag, the L2 learning module updates the L2 learning table to create a new entry defining an association between the one of the interfaces that received the packet and the service tag.