HP-UX Reference (11i v2 04/09) - 4 File Formats (vol 8)

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gated.conf(4) gated.conf(4)

OSPF uses the destination address and the type of service to choose the best route to the destination.

OSPF intra- and inter-area routes are always imported into the GateD routing database with a prefer-

ence of 10. It would be a violation of the protocol if an OSPF router did not participate fully in the OSPF

of the area, so it is not possible to override this. Although it is possible to give other routes lower prefer-

ence values explicitly, it is ill-advised to do so.

Hardware multicast capabilities are also used where possible to deliver link-status messages. OSPF

areas are connected by the backbone area, the area with identiﬁer 0.0.0.0. All areas must be logically con-

tiguous and the backbone is no exception. To permit maximum ﬂexibility, OSPF allows the conﬁguration

of virtual links enable the backbone area to appear contiguous despite the physical reality.

All routers in an area must agree on the parameters of that area. A separate copy of the link-state algo-

rithm is run for each area. Because of this, most conﬁguration parameters are deﬁned on a per area

basis. All routers belonging to an area must agree on the conﬁguration of that area. Misconﬁguration will

lead to adjacencies not forming between neighbors, and routing information might not ﬂow, or even loop.

Authentication

All OSPF protocol exchanges are authenticated. Authentication guarantees that routing information is

only imported from trusted routers, to protect the Internet and its users. A variety of authentication

schemes can be used but a single scheme must be conﬁgured for each area. This enables some areas to

use much stricter authentication than others. OSPF protocol exchanges may be authenticated. Authenti-

cation guarantees that routing information is imported only from trusted routers, to protect the Internet

and its users. There are two authentication schemes available. The ﬁrst uses a simple authentication key

of up to 8 characters and is standardized. The second is still experimental and uses the MD5 algorithm

and an authentication key of up to 16 characters.

The simple password provides very little protection because in many cases it is possible to easily capture

packets from the network and learn the authentication key. The experimental MD5 algorithm provides

much more protection as it does not include the authentication key in the packet.

The OSPF speciﬁcation currently speciﬁes that the authentication type be conﬁgured per area with the

ability to conﬁgure separate passwords per interface. This has been extended to allow the conﬁguration of

different authentication types and keys per interface. In addition it is possible to specify both a primary

and a secondary authentication type and key on each interface. Outgoing packets use the primary

authentication type, but incoming packets may match either the primary or secondary authentication

type and key.

The OSPF Statement

ospf yes | no | on | off [ {

defaults {

preference preference ;

cost cost ;

tag [ as ] tag ;

type 1 | 2 ;

};

exportlimit routes ;

exportinterval time ;

traceoptions trace_options ;

monitorauthkey authkey ;

monitorauth none |([simple | md5 ] authkey ) ;

backbone |(area area ) {

authtype 0 | 1 | none | simple ;

stub [ cost cost] ;

networks {

network [ restrict ] ;

network mask mask [ restrict ] ;

network masklen number [ restrict ] ;

host host [ restrict ] ;

};

stubhosts {

host cost cost ;

};

interface interface_list;[cost cost ] {

interface_parameters

HP-UX 11i Version 2: September 2004 − 19 − Hewlett-Packard Company Section 4−−95