Re: ospf neighbor not working

daniel4579329 · ‎08-19-2020

hi

im learning for the ccna and im working on ospf and i cant make R2 to learn routes via ospf on port fa1/0 no i tried to do this via the network command and also via the command under the port can someone look at the packet tracer file and tell me what i dont see

thanks for the help (:

Farhan64 · ‎08-19-2020

Hi,

YOUR FA1/0 IP ADDRESS IS NOT PROPER

Router#sh ip ospf neighbor

THIS IS WHAT FA1/0 IS SHOWING BEFORE CORRECTING THE IP ADDRESS

Router#sh ip interface f1/0

FastEthernet1/0 is up, line protocol is up (connected)

Internet address is 200.20.0.1/8

Broadcast address is 255.255.255.255

AND YOUR NEIGHBOUR TABLE

Router#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

10.12.0.1 1 FULL/BDR 00:00:36 100.0.0.1 FastEthernet0/0

Router#sh ip protocols

Routing Protocol is "ospf 1"

Outgoing update filter list for all interfaces is not set

Incoming update filter list for all interfaces is not set

Router ID 200.20.0.1

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

Maximum path: 4

Routing for Networks:

100.0.0.0 0.255.255.255 area 0

200.20.0.0 0.0.0.255 area 0

11.0.0.0 0.255.255.255 area 0

Routing Information Sources:

Gateway Distance Last Update

10.12.0.1 110 00:01:16

200.20.0.1 110 00:01:16

Distance: (default is 110)

Neighbor ID Pri State Dead Time Address Interface

10.12.0.1 1 FULL/BDR 00:00:36 100.0.0.1

YOUR IP WAS 200.20.0.1/8 and

AND YOUR NEIGHBOR MASK IS /24

OSPF routers cannot form neighbor relationship due to a mismatch in Hello or Dead parameters. Following parameters in Hello packets should match between neighboring routers:

Hello and Dead intervals
Area ID
Authentication type and password
Stub Area flag
Subnet ID and Subnet mask

SUBNET MASK WAS WRONG.. CORRECT IT

Router(config-if)#ip address 200.20.0.1 255.255.255.0

Router#sh ip interface f1/0

FastEthernet1/0 is up, line protocol is up (connected)

Internet address is 200.20.0.1/24

Broadcast address is 255.255.255.255

here is your neighbour table

Router#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

200.20.0.3 1 FULL/BDR 00:00:35 200.20.0.3 FastEthernet1/0

200.20.0.2 1 2WAY/DROTHER 00:00:35 200.20.0.2 FastEthernet1/0

200.20.0.4 1 FULL/DR 00:00:35 200.20.0.4 FastEthernet1/0

10.12.0.1 1 FULL/BDR 00:00:35 100.0.0.1 FastEthernet0/0

Martin L · ‎08-19-2020

as mentioned above, you have wrong /8 mask but others have /24. To exchange routes, OSPF and other protocols must be on the same network/link.

change mask to 255.255.255.0 on R2's interface FastEthernet1/0 with ip address 200.20.0.1

Regards, ML
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