2 entries are registered on port 445. It is a well-known port (0–1023) — assignments here are IANA's, and a service found on one is usually the service that was assigned it.
services registered on this number
1 transport in use
entries encrypted on the wire
2 of 2 iana-registered
| port | service | proto | category | risk | views |
|---|---|---|---|---|---|
| :445 | Microsoft-DS / SMB | TCP | File Transfer | caution | 22.3k |
| :445 | SMB over Microsoft-DS | TCP | File Transfer | caution | 21.1k |
Port 445 is primarily used for Microsoft Directory Services (Microsoft-DS), supporting file sharing, printer sharing, and access to Active Directory via the Server Message Block (SMB) protocol over TCP. It has replaced older NetBIOS ports, facilitating more efficient direct communication, and is widely deployed across Windows environments for seamless network resource access.
port 445 as Microsoft-DS / SMB →Port 445 is primarily used for Microsoft Directory Services (Microsoft-DS), which facilitates file sharing, network browsing, and network communication via the Server Message Block (SMB) protocol over TCP/IP without requiring NetBIOS. It is essential for Windows-based file and printer sharing and is widely used in corporate environments for resource sharing and network management.
port 445 as SMB over Microsoft-DS →The registry says what 445 is registered to. What is listening on it right now is decided by the host, and only the host can be asked. Each of these prints the process behind the socket.
ss -ltnp | grep ':445\b'lsof -nP -iTCP:445 -sTCP:LISTENnetstat -ano | findstr :445On Linux and Windows the process name comes back with the socket; on macOS lsof needs sudo to name a process that isn't yours. Match what it prints against the 2 entries above.
A port number is not a service. Anything may listen on 445 — what you actually met is decided by the host, not the registry. If a service is missing here, it belongs in the registry.
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