Canon LBP6780x Manual page 444

Check the key used for SSL.
See "Setting Keys and
registration and selection procedures.
Proxy Settings
(1) Click [Edit...] in [Proxy Settings].
(2) Set proxy functions.
When using proxy functions
Select the [Use Proxy] check box, and set the following items.
[HTTP Proxy Server
Address]
[HTTP Proxy Server
Port Number]
[Use Proxy within
Same Domain]
Certificates" for more information about SSL encrypted communication functions and key
Enter the address of the proxy server used by the proxy functions.
Enter the port number of the proxy server used by the proxy functions. You can set
it between [1] and [65535].
When the check box is selected, use the proxy function within the same domain.