These ports need to be opened in your firewall for Samba to be functional.
- UDP
137 / udp / NetBIOS Name Service
138 / udp / NetBIOS Datagram Service
- TCP
139 /tcp / NetBIOS Session Service
445 /tcp / Microsoft Directory Service
- for Samba Web Administration
901 / tcp / SWAT
If you use ISPConfig Hosting Control Panel, just go to Management / Services / Firewall, and add a firewall rule. One note: Besides the fact that help info said different, the port range can not be used when specifying UDP port – it’s a bug – see this thread)