L2L Connection Flapping Between Interfaces

[alowery.2.9872]

Hello,

I want to start by apologizing as I am by no means a networking professional. 

We have been having issues recently with our primary ISP, and have been trying to setup a connection to use as a failover.

We seem to be running into a problem with the l2l connection coming up and going down, and not being in a consistent state.

I've attached some of the debug files for reference(they may or may not help); it seems to occur even with one of the interfaces shutdown.

Can anyone point myself in the correct direction to get this resolved?

I have been referencing the CLI support document in the link:

https://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/118962-configure-asa-00.html

Edit: asa1 is a 5512 running  9.6, asa2 is a 5512 running 9.2

[Deepak Kumar]

Hi,

I went through the ASA2 debug message and found an issue "IKE COMMON DEBUG]Duplicate entry already in Tunnel Manager"

You can try with adding below commands at both ends:

crypto isakmp disconnect-notify