I had this working... I thought. I matched the traffic statistics on one of my Cisco ASA site-site tunnels with the OID:184.108.40.206.220.127.116.11.18.104.22.168.22.214.171.12442 (cipSecTunHistInOctets). I was real proud of myself for a few days until I checked the history and found the OID wasnt working..
After some troubleshooting I found that the last four digits (4142 in this case) change whenever the tunnel drops and re-establishes itself.
Has anyone managed to figure out a way to collect tunnel utilization history on an ASA with SNMP? Is there a different OID I can use thats based on the endpoint IP?