Hello @Choi, Sung-Pil
SMB ports are generally port numbers 139 and 445.
Port 139 is used by SMB dialects that communicate over NetBIOS. If you have old clients in your network, the earlier version of SMB (SMB 1.0) was originally designed to operate on NetBIOS over TCP/IP , which uses port TCP 139 for session services.
Port 445 is used by newer versions of SMB (after Windows 2000) for direct SMB over TCP/IP.
You can check if a port is open by using the netstat command.
(If both NetBIOS over TCP/IP and directly hosted SMB over TCP/IP are available (that is, if ports 445 and 139 are both listening), Windows tries both options at the same time. Whichever responds first is used for communication.)
Here’s a table summarizes all the service ports in case you needed: