Avaya 8800 Planning And Engineering page 194

Multicast network design
Figure 85: Static mroute
The system does not advertise or redistribute routes from the multicast-static IP route table.
The system uses these routes only for RPF calculation. The system uses the following rules
to determine RPF:
• Direct or local routes for a destination take precedence over a route for the same
destination in the static route table.
• If a route exists in the static route table, and no route exists in the unicast routing table
for the destination, the system uses the route in the static route table.
• If a route is available in both the unicast routing table and the static route table, the system
uses the route from the static route table only if the administrative distance is less than
or equal to that of the unicast route entry.
• If no route exists in the static route table for the destination, the system uses the route
from the unicast routing table, if available.
• The system performs a longest prefix match during a lookup in the static route table. The
lookup ignores routes that are administratively disabled.
• After the system performs a lookup within the static mroute table, if multiple routes exist
for a matching prefix, the system chooses the route with the least preference. If multiple
routes exist with a matching prefix and the same preference, the system chooses the
route with the highest RPF address. This selection method only occurs within the static
mroute table; the system still compares the selected route with a route from RTM, if one
exists.
194 Planning and Engineering — Network Design November 2010