To delete a single NAT policy, click the Delete icon (trash can) in the Configure column of the NAT Rules entry. If the icon is dimmed, the NAT policy is a default entry, and you cannot delete it.
To delete one or more custom NAT policies, select the checkboxes of the policies and click Delete at the bottom of the table.
To delete all custom policies, click the top left checkbox in the NAT Rules table. All custom policies are selected. Click Delete or Delete All at the bottom of the table.
Default policies cannot be deleted.