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New Member

Error message on cisco 4500 router

Dear all,

Kindly help out to parse the following error message I found in my router.I am running OSPF in my network and could anyone pls inform me what could be wrong seeing this error msg,

2d00h: %CRYPTO-6-IKMP_MODE_FAILURE: Processing of Main mode failed with peer at

The ip which is mentioned in the mssg has nothing to do with my network.




Re: Error message on cisco 4500 router

You have a mismatch in crypto attributes on both sides. Make sure encryption algo, authentication algo, hashing etc. are same on both sides.

Also debug ISAKMP and see if you can glean into specific details.


New Member

Re: Error message on cisco 4500 router

The explanation of your router error can be verified from cisco's output intepreter as follows:

%CRYPTO-6-IKMP_MODE_FAILURE (x1): Processing of [chars] mode failed with peer at [IP_address]

Explanation: Negotiation with the remote peer has failed.

I hope this helps.

Ngembus D

Network Engineer, Nettek System Consultants.

Re: Error message on cisco 4500 router

If this is a production network, and this router is running several other tunnels (which are up), I would not recommend using debug commands, during peak hours. Trying doing debugs only after hours, or during a downtime window, incase if the router stops responding.

The debug command you can use is,

debug crypto isakmp

If you can paste the output here, we can find out what the problem is.

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