The (conceptual) table containing objects specific to a PIM
domain. One row exists for each domain to which the router
is connected. A PIM-SM domain is defined as an area of the
network over which Bootstrap messages are forwarded.
Typically, a PIM-SM router will be a member of exactly one
domain. This table also supports, however, routers which
may form a border between two PIM-SM domains and do not
forward Bootstrap messages between them.