Installing and Administering Internet Services

Chapter 8 355
Configuring gated
Configuring the OSPF Protocol
routerdeadinterval 20 ;
retransmitinterval 10 ;
pollinterval 20 ;
} ;
} ;
} ;
Defining Backbones
The OSPF backbone distributes routing information between areas.
Backbones are defined with the same statements and clauses as areas.
The stub statement may not be defined for a backbone. The backbone
statement is used to define a router as a backbone router. If an OSPF
internal or area boarder router is also a backbone router, the backbone
statement must follow the area statement(s) in the /etc/gated.conf
file. Whenever an area border router (a router connected to multiple
areas) is configured, backbone information must be provided.
Figure 8-10 shows an example of two area border routers that form part
of a backbone. Router A has interfaces to both area 0.0.0.1 and area
0.0.0.2, while router B has interfaces to areas 0.0.0.3 and 0.0.0.4. Router
A is connected to router B through interface 15.13.115.156.