Chapter 1 What’s New for FortiOS 5.2.1 : System Features : FortiGuard Services : Using TCP Port 80 to Receive Updates from a FortiManager Unit
  
Using TCP Port 80 to Receive Updates from a FortiManager Unit
Communications to a FortiManager unit in order to receive FortiGuard updates are now supported using TCP port 80.
To configure communications to use port 80, go to System > Config > FortiGuard and expand Web Filtering and Email Filtering Options. Select Use Alternate Port (80). This can also be configured using the CLI.
Syntax
config system fortiguard
set port 80
end
FortiGuard TCP stats can also be displayed using the diagnose test application urlfilter 20 command.