Created on 01-31-2022 10:22 AM Edited on 11-06-2024 10:55 PM By Jean-Philippe_P
Description |
This article explains how to resolve an OSPF neighbor issue where the OSPF is stuck in the INIT state.
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Scope |
FortiGate v6.2. FortiGate v7.6. |
Solution |
See one of the following articles if an OSPF neighbor is stuck in one of the other states:
OSPF uses multicast IP 224.0.0.5 to send HELLO to its neighbor(s). Sometimes, the multicast packets can get dropped between the source and destination. When this happens, the other side will not receive the HELLO packets and will therefore be unable to pass the INIT state. For clarity, these are the states OSPF routers pass through to form neighbors:
Until the neighbors are in FULL State, the network will not function.
Neighbor routers get stuck in an INIT state when an OSPF router fails to receive its neighbor HELLO packets. This can be due to a couple of reasons. Below are some common causes and suggested solutions.
Reference: Technical Tip: How to configure OSPF over Non-Broadcast link.
Check the MTU and, if it is different, set the OSPF neighbors to ignore MTU. Alternatively, adjust the MTU to the same size.
The following commands assist with troubleshooting an OSPF stuck in an INIT state: Note: Run this on both neighbors.
get router info ospf interface
Example:
get router info ospf interface portX is up, line protocol is up Internet Address 192.168.X.Y/30, Area 0.0.0.0, MTU 1500 Process ID 0, VRF 0, Router ID 192.168.X.Y, Network Type POINTOPOINT, Cost: 1 Transmit Delay is 1 sec, State Point-To-Point Timer intervals configured, Hello 10.000, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:08 Neighbor Count is 0, Adjacent neighbor count is 0 Crypt Sequence Number is 7900942 Hello received 14467 sent 75124, DD received 780 sent 906 <<<<<< HELLOs are being dropped. LS-Req received 78 sent 261, LS-Upd received 27423 sent 376 LS-Ack received 298 sent 24409, Discarded 0 Cryptographic authentication enabled <-- Authentication is configured Sending SA: Key 1
diag sniffer packet any 'host 224.0.0.5' 4
Example of 1-way HELLOs:
Line 26: 2.523359 portX out 192.168.X.Y -> 224.0.0.5: ip-proto-89 60 |
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