IPSec Child-SA rekey negotiation fails

[Purushotham]

Our customer encounter intermittent connectivity issue with IPSec IKEv1 during phase 2 rekey of IPSec Child-SA. We open case with the IPSec peer device vendor, they mention that PAN is not sending message to R2011 (IPSec peer) for deleting the SA when the SA negotiation fails.

Summary of issue:

• On IPsec PA-850 peer device log, it shows IKE phase-2 negotiation is failed as responder, Due to negotiation timeout for that child-SA]
• On IPsec 4G router side SA rekey log it shows child-SA is successful established/rekey
• During that 1 hour Proxy-ID traffic for that Child-SA is down. Traffic resume on next successful Child-SA rekey, SA lifetime 1 hour.
• From debug log (as below) negotiation timeout on PA-850 trigger by intermittent packet transmission loss on Telco 4G mobile network. 

Highlight event log of “the sent the delete key message to the peer and started the negotiation as a responder.

1.re key at 5.00.07 of Child SA as responder for Proxy ID 2. Failed as negotiation as responder and didn’t send p2 delete message to peer.

2.Next re key at 5.39.12 of Child SA as responder for Proxy ID 2. Observe no existing SA (previous negotiation fail at 5.00.07am), so didn’t send p2 delete message to peer after successful rekey.

So, please advise on this behavior of the PA as a responder.

[JayGolf]

Hi @Purushotham ,

Thanks for your question. I would verify that the PA-850 and peer are using compatible IPSec settings, such as encryption algorithms, key lifetimes, and authentication methods, Proxy IDs, and other parameters related to phase 2 negotiation.

If you've verified the settings are good to go and you are still experiencing issues, I recommend creating a support case for this issue.