You would like to know the limitations on HTTP request headers on the ProxySG or Advanced Secure Gateway (ASG) appliance.
For versions earlier than SGOS 6.6, the maximum size for an HTTP request header is 8KB. For SGOS 6.6, the maximum size is 128KB. There is also a limit of 125 request headers. So, if the HTTP request exceeds 125 request headers OR 128KB, the request will be denied.