Q: How do I setup the filters based ip address ?
A: In the "Security" section of  "Tftp" tab or "Telnet" tab , You can Add/Edit/Delete Filters，select Action (Permit/Deny),Ip address and Subnet mask, All filters will be executed with its order .

Q: How can I know the extended telnet command ?
A: You can telnet to the Quick Tftp Server Pro, and input ? or help, all extended command will be displayed.