OSPF on FR

Just Kennie · ‎05-30-2009

I have an OSPF FR network of one hub and two spokes. The FR is non-broadcast as broadcast is not defined on the layer 3 to layer 2 mapping. So I configured neigbour statement on the Hub to have OSPF adjaceny. It worked. I notice that when I remove the neighbour statement, the adjaceny did not go down btw the hub and spoke, even after clearing the OSPF process.

1. How did the adj continue to from on the FR (without broadcast statement on the Layer 3 to layer 2 mapping), even after removing the neighbour statement on the hub.

2.In a NBMA FR network like this with broadcast statement on the layer 3 to layer mapping, apart fron defining neighbour statement under ospf process, what can be done to achieve ospf adjaceny.

3.Does OSPF sends hello and update through multicast.

Edison Ortiz · ‎05-30-2009

1. Did you disable 'frame-relay inverse-arp'? Perhaps you have additional dynamic mappings on the router.

Check with 'frame-relay mapping'. You can also bounce the interface or the router and see if the OSPF adjancency is maintained. Did you wait 3 minutes for the neighbors to go down?

2. You can use 'ip ospf network point-to-multipoint' or 'ip ospf network broadcast' under the frame-relay interface.

http://www.cisco.com/en/US/docs/ios/iproute/command/reference/irp_osp2.html#wp1011948

3. OSPF sends updates to 224.0.0.5 (AllSPFRouters)

and

224.0.0.6 (AllDRouters) when a segment is a broadcast or non-broadcast network type.

HTH,

__

Edison.