I have 5 windows 8 machines across various domains all configured with 8-10 L2TP VPN setups to various clients networks. Most of them are to Sonicwall firewalls but a couple are to other firewalls. My Windows 8 machines consists of both upgrades from Windows 7 and fresh installs. Either way every one of my L2TP connections will disconnect at 60 minute increment, regardless of activity or inactivity, which never happened on Windows 7. I have looked everywhere on the Sonicwalls (all of them are on the most up to date firmware) and there is no setting for disconnecting after 60 minutes.
The issue must be with Windows 8 - just looking for a registry hack or hotfix that will fix this problem.
Michael E. Wheeler