Installing and Administering Internet Services

266 Chapter 8

Conﬁguring gated

Conﬁguring the OSPF Protocol

deﬁnition applies to both X.25 network interfaces as well as for systems

that do not support IP multicast. An NBMA type interface is deﬁned

with the same statements as for a multicast type interface, with the

following additions:

• The clause nonbroadcast must be speciﬁed in the interface

statement.

• pollinterval speciﬁes a rate at which hellos are sent when a

neighboring router becomes inactive. (A router is considered inactive

when hellos have not been received from the router for the amount of

time speciﬁed by the routerdeadinterval deﬁnition.) The value of

pollinterval should be larger than the value of hellointerval.

A sample value for an X.25 network is 2 minutes.

Default: None (you must specify a value)

Range: 0 - 255

• routers speciﬁes the list of routers that are attached to the

non-broadcast network. Routers are deﬁned by their IP interface

addresses. Routers that are eligible to become Designated Routers

must be deﬁned as eligible.

Figure 8-7 shows an example of a router (A) that is connected to an

NBMA network through interface 193.2.1.35. Two other routers are also

attached to the network: router B is connected through interface

193.2.1.33 and C is connected through interface 193.2.1.46. B and C are

eligible to be Designated Routers.