DOCUMENT:Q159659  09-AUG-2001  [winnt]
TITLE   :Unable to Establish Adjacency with Neighboring OSPF Routers
PRODUCT :Microsoft Windows NT
PROD/VER:WinNT:4.0
OPER/SYS:
KEYWORDS:kbnetwork

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The information in this article applies to:

 - Microsoft Windows NT Server version 4.0 
 - Microsoft Routing and Remote Access Service Update for Windows NT Server version 4.0 
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SUMMARY
=======

This article provides troubleshooting ideas for OSPF routers that are not able
to establish an Adjacency. An Adjacency is established when the Link State
database of neighboring routers is fully synchronized.

1. Ping the neighboring router to ensure basic network connectivity.

2. Windows NT OSPF routers have Authentication enabled by default. The default
   password is 12345678. Be sure to change the Authentication to match all
   neighboring OSPF routers. The password is configured on a per- interface
   basis on the General tab. Passwords are case sensitive.

3. Be sure that the Hello and Dead intervals match the Hello and Dead intervals
   of neighboring OSPF routers. By default the Hello interval is 10 seconds and
   the Dead interval is 40 seconds. These intervals are configured on a
   per-interface basis in the Advanced tab.

4. Be sure that area border routers (ABR) are on the backbone 0.0.0.0. Area
   border routers are routers that are part of two or more different OSPF areas.
   An ABR does not have to be physically on the backbone if a virtual link has
   been created, attaching it to the backbone. Virtual links are configured
   globally on the Virtual Interfaces tab. Virtual neighbors must be configured
   using the router ID, not just any IP address.

5. If the routers are on a non-broadcast multi access (NBMA) network, such as
   X.25 or frame relay, their neighbors must be manually configured because
   neighbors are unable to be found through multicast. Neighbors are configured
   on a per-interface basis on the Neighbors tab. Neighbors must be configured
   using the IP address of the neighbor to which the link state information
   needs to be sent.

6. If you have an NBMA network, such as X.25 or frame relay, that is in a hub
   and spoke configuration, be sure to set the router priority on spoke routers
   to 0 and the hub router to 1 or greater. A router priority of 0 means that
   the router cannot become a designated router (DR) . The hub router must be
   the DR because it is the only router that can communicate directly with all
   other routers. The router priority defaults to 1 and is set on a
   per-interfaces basis on the General tab.

7. On broadcast (token ring, Ethernet, FDDI) or NBMA networks (X.25, frame
   relay), be sure that all routers do not have a priority of 0. At least one
   router needs a priority of 1 or greater to become the designated router.

8. Be sure neighboring routers are configured correctly with the same area ID.

9. When you configure an OSPF router, be careful not to duplicate router
   identification numbers. The router identification number should uniquely
   identify a router throughout the OSPF autonomous system.

Additional query words: RRAS

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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbAudDeveloper kbRRASNTSearch kbRRASNT400
Version           : WinNT:4.0

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