User`s guide

9-8 Preliminary November 23, 1998 MultiVoice Gateway for the MAX— User’s Guide
Configuring OSPF Routing
Introduction to OSPF
6 Refer to the documentation that came with your MultiVoice Gateway.
7 In this static route profile, specify whether you want to advertise this route outside the
NSSA:
– To advertise this route outside the NSSA, set NSSA-Type to Advertise.
– To not advertise this route outside the NSSA, set NSSA-Type to DoNotAdvertise.
8 Exit and save the Static Rtes profile.
9 Reset the MultiVoice Gateway.
The link-state routing algorithm
Link-state routing algorithms require that all routers within a domain maintain synchronized
(identical) topological databases, and that the databases describe the complete topology of the
domain. An OSPF router’s domain can be an AS or an area within an AS.
OSPF routers exchange routing information and build Link-state databases. Link-state
databases are synchronized between pairs of adjacent routers (as described in “Exchange of
routing information” on page 9-4). In addition, each OSPF router uses its link-state database to
calculate a self-rooted tree of shortest paths to all destinations, as shown in Figure 9-6.
Figure 9-6. Sample network topology
The routers then use the trees to build their routing tables, as shown in Table 9-1.
Table 9-2, Table 9-3, and Table 9-4 show another example of self-rooted shortest-path trees
calculated from link-state databases, and the resulting routing tables. Actual routing tables also
contain externally derived routing data, which is advertised throughout the AS but kept
Table 9-1. Link state databases for network topology in Figure 9-6
Router-1 Router-2 Router-3
Network-1/Cost 0 Network-2/Cost0 Network-3/Cost 0
Network-2/Cost 0 Network-3/Cost0 Network-4/Cost 0
Router-2/Cost 20 Router-1/Cost 20 Router-2/Cost 30
Router-3/Cost 30