FRITZ!Box 6430 Cable Service - Knowledge Base
Shared files and printers on a computer are not available over the Internet
You cannot access shared files and printers on remote computers over your FRITZ!Box's Internet connection. Other connections using the SMB or CIFS protocol also cannot be established over the FRITZ!Box's Internet connection, for example connections to Strato HiDrive. Connections from the Internet to the home network that use the SMB or CIFS protocol are also not possible.
1 SMB/CIFS protocol is blocked for security reasons
In order to guarantee the security of the computers in the home network, the FRITZ!Box blocks all access over the Internet to the TCP and UDP ports 139 and 445 ("NetBIOS Filter") that are used for file and printer sharing. Therefore, you cannot use applications in the home network that use the SMB or CIFS protocol to exchange data with the Internet.
- Configure the respective application so that it uses secure transfer protocols such as VPN, HTTPS, or SFTP instead of the SMB or CIFS protocol. Refer to the manufacturer for information on the necessary settings, for example consult the manual.