Installing and Administering Internet Services

Chapter 8 357
Configuring gated
Configuring the OSPF Protocol
implementations, a “virtual link” can be configured to join
non-contiguous backbone routers. Virtual links are not supported on
HP-UX systems.
Authentication
The OSPF protocol allows packets containing routing information to be
authenticated. The authentication method used is configured on a
per-area basis; different authentication methods may be used in different
areas.
gated supports a simple password authentication method. You can also
choose to have no authentication. The authtype statement is used to
define the authentication method used for the area. 0 or none specifies
that routing exchanges in the area are not authenticated. 1 or simple
specifies that network passwords of up to 64 bits (8 characters) are used
to authenticate packets received from routers in the area.
In the simple password authentication method, all routers that interface
to a given network use the same password. The password is defined by
the authkey statement in the router’s interface definition. If a router is
not configured with the same password as other routers in the network,
the router’s packets are discarded by other network routers. Note that
the password is configured on a per-interface basis. If a router has
interfaces to more than one network, different passwords may be
configured. This is illustrated in Figure 8-11.