I am using tplink ddns which it shows is successfully bound. But i am unable to access my pendrive either through local or external network with the tplink ddns as a ftp server. Where as I'm able to access it from ftp(local address) and smb also. If i use any other d dns like noip i am able to access server from ftp via internet only if connect to local network and not if i try from any other sim or wifi