A ProxySG or Advanced Secure Gateway(ASG) has 2 major categories of restarts.
Some restarts are caused by the ProxySG or ASG running into a problem with how to handle something. Those sometimes become bugs that are fixed by engineering.
Other times, the ProxySG or ASG will restart itself as a proactive measure taken against a metric that has become abnormal. For example, if the CPU utilization remains close to 100%, or if memory pressure stays high for a certain period of time, the ProxySG or ASG will restart itself.
As of today, ProxySG or ASG restarts or crashes are not self-serviceable, to know the root cause of a restart, tech support has to be involved. There are things that can be done to ensure that the right information is uploaded at the right time. Here is the procedure on how to make sure tech support has all the required information in hand to figure out the root cause of the restart
As soon as you are aware that the ProxySG or ASG has restarted, open a new service request (via the phone or MySymantec portal). As soon as you have the service request number, go to the ProxySG or ASG management console: