can use the following procedure to configure static mroutes. Static mroutes are
similar to unicast static routes but differ in the following ways:
are used to calculate RPF information, not to forward traffic.
cannot be redistributed.
mroutes are strictly local to the
device on which they are defined. Because
Protocol Independent Multicast (PIM) does not have its own routing protocol,
there is no mechanism to distribute static mroutes throughout the network.
Consequently, the administration of static mroutes tends to be more complicated
than the administration of unicast static routes.
When static mroutes
are configured, they are stored on the
device in a separate table referred to as
the static mroute table. When configured, the ip mroute command enters a static mroute into the
static mroute table for the source address or source address range specified
for the source-address and mask arguments. Sources that match the source
address or that fall in the source address range specified for the
source-address argument will RPF to either the interface associated with the IP
address specified for the
argument or the local interface on the
device specified for the
interface-number arguments. If an IP address is specified
argument, a recursive lookup is done from the unicast routing table on this
address to find the directly connected neighbor.
If there are
multiple static mroutes configured, the
device performs a longest-match lookup of
the mroute table. When the mroute with the longest match (of the
source-address) is found, the search terminates and the information in the
matching static mroute is used. The order in which the static mroutes are
configured is not important.
distance of an mroute may be specified for the optional distance argument. If a
value is not specified for the distance argument, the distance of the mroute
defaults to zero. If the static mroute has the same distance as another RPF
source, the static mroute will take precedence. There are only two exceptions
to this rule: directly connected routes and the default unicast route.