We have recently come across an interesting issue between a Cisco ASA ikev2 tunnel with a PA.
If I was to failover the PA to an HA peer, traffic initiated from the Cisco ASA continues to flow whilst traffic initiating from the PA stops.
I noticed when the PA fails over the ASA drops both phases and recreates them with a new SPI value whilst the PA continues to use the same SPA value. PA manages to change its SPA value to match the new SPI value only for traffic that originates from the ASA although traffic from the PA continues to use the same SPA value which causes the traffic to not be sent.
My fix currently is by resetting the problematic proxy ID's from PA.
I have a case open with PA although has anyone come across this before as I assume this would be a common problem faced.
Cisco ASA 9.8.4.xx, PA 10.1.4-h4
Hi @ITforacompany ,
Have you configured Liveness Check under Network > Network Profiles > IKE Gateways > [edit gateway] > Advanced Options? I have that set to 5 seconds on an IPsec tunnel to an FTD device which is has much of the same code as an ASA. https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClgcCAC
The ASA may need the "crypto ikev2 dpd interval retry-interval" command configured. I can't remember if it is default.
They did and it was drawn out. They deem this issue is just between Cisco ASA's and PA's. All other parties are not affected although yet to be tested.
Their reply to CASE 02120653
"The root of this problem is due to IKE phase 1 SA information NOT synchronized between the Palo Alto Networks HA firewalls (only IPSEC phase 2 SAs are synchronized between HA firewalls)."
Their initial answer was to disable the liveness check and DPD which after failing over the PA pairs did work although the issue arose again when the ASA rekeyed. The traffic dropped again for the proxy ID traffic that was originating behind the PA. This is due to the phase 1 details not being syncing between the HA pairs. The only fix at the moment is to manually run "test vpn ipsec-sa" from PA.
I am pushing our account rep to add it as a hotfix.
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