Since the upgrade to 6.2.5.1-26n the pre-shared key renegotiation at the lifetime expiration takes between 3 to 5 minutes. The tunnel will then come back up on its own but the traffic is likely to be dropped in this interval.
Should you face this issue, you can contact our Technical Support team about DTS#174726 and request the HF#174726-1n for Gen6 or Gen5 appliances.
There are two ways to contact technical support:
1. Online: Visit mysonicwall.com. Once logged in select Resources & Support | Support | Create Case.
2. By phone: please use our toll-free number at 1-888-793-2830. Please have your SonicWall serial number available to create a new support case.
If you do not have a mysonicwall.com account create one for free!
Fixed in SonicOS 6.2.5.2-27n