Cisco 300-420 Online Access

The PIM mode that uses a shared tree only is the sparse mode. In sparse mode, PIM routers build a shared tree for multicast traffic, which is shared among all of the routers in the multicast domain. The shared tree is built from the source routers to the rendezvous point (RP) and then from the RP to the receivers. The advantage of sparse mode is that it requires less state information on the routers.

There are 3 types of border nodes in SD-Access:

External. Default exit from fabric with no specific routes injection

Internal. Gateway only for a set of networks, such as shared services prefixes

Anywhere. Combination of external and internal functionality