Understanding the network.pdf - Back to Home

or from a specific set of networks. Applying an inbound route filter will suppress any
unauthorized networks from being injected into the routing table.
Here are inbound filter examples using OSPF and RIP (see Figure 10.9). ABR-a57 is
filtering announcements from ir-23 and ir-24. Only the 192.168.x.0 networks
need to be accessible throughout the network. The 10.0.x.0 networks are used for
local testing and only need to be available to the networks directly connected to
ir-33 and ir-34. The first router configuration example shows OSPF using an
inbound distribution list to suppress the addition of the 10.0.x.0 routes on the local
routing table. The next example shows the same thing with RIP. The RIP usage of
the inbound command also prevents the 10.0.x.0 routes from
being announced to ABR-a58 and ABR-a56:
Figure 10.9. A campus backbone network example
for using the route
distribution/suppression command.