Static neighbors in OSPF

[jfullwood]

I have been reading the CCNP Route 642-902 Official Certification Guide by Wendell Odem.  In that book the author discusses static neighbors under EIGRP and how once one neighbor is statically configured, dynamic discovery is disabled on that segment.  Does the same apply to OSPF network segments when static neighbors are configured?

[Adrian Lazar]

Things are a little different in OSPF regarding the static neighbors because they are meant only for non-broadcast networks where the routers cannot multicast the hello packet and find the neighbors on the segment. On a broadcast network you are not allowed to use the neighbor command.

[lgijssel]

Yes, this is indeed the case.

Typically this is used on NonBroadcast networks (frame relay, atm hub-spoke) where a neighbor cannot be discovered in the "normal" fashion. On a broadcast network you cannot use the neighbor command.

Feel free to check the gns3-lab for which the topology has been attached for an example of this scenario.

regards,

Leo

[jfullwood]

Thanks for you replay.  I will check out your link.  I realize that static neighbors are normally used in NBMA environments, however, the EIGRP discussion in the book talked about using static neighbors as a way to limit multicast traffic on a slow link.  That is why a clear statement was made about the use of a neighbor statement in a broadcast environment.  That is once you define a static neighbor on a segment, all of the neighbors must be defined statically, because dynamic neighbor discovery is disabled.

Regards,

JohnF.

[cadet alain]

Leo,

On a broadcast network you cannot use the neighbor command

If you change the ospf network type to non broadcast then you can use static neighbours, no ?

Regards.