we had Cisco ASA5550 in Active/standby mode which worked without any issue for over 1 year. Recently, we started having issue where the VPN tunnels would drop to sites and have internet outages. We disabled failover and took Standby ASA out of the network. While the network is operating on one ASA, it rebooted itself without any reason. I am unable find the reason behind logs were erased on reboot. i can confirm there wasn't a power issue as nothing else power cycled. ASA version: 9.1(5)
Is there any known bug fix? what could case ASA reboot itself?
Thanking you in advance.