You can enable or disable a Generic Routing Encapsulation (GRE) traffic whitelist by using the Network Security appliance Web UI or CLI:
When GRE traffic is enabled on the Network Security appliance, all GRE packets are whitelisted. When GRE traffic is disabled on the Network Security appliance, GRE packets are not whitelisted.
Note
A GRE traffic whitelist is disabled by default.
Prerequisites
Administrator or Operator access to the Network Security appliance.