2 entries are registered on port 911. 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
2 transports in use
entries encrypted on the wire
1 of 2 iana-registered
| port | service | proto | category | risk | views |
|---|---|---|---|---|---|
| :911 | NCA over OpenSSH | TCPtls | Security | caution | 7.1k |
| :911 | Xact Backup | TCPUDP | — | safe | 0 |
Network Console on Acid (NCA) over OpenSSH provides a way to redirect local TTY consoles over secure SSH tunnels, enabling remote system management while leveraging encrypted communications for enhanced security.
port 911 as NCA over OpenSSH →Xact Backup uses TCP and UDP port 911 for backup traffic.
port 911 as Xact Backup →The registry says what 911 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 ':911\b'lsof -nP -iTCP:911 -sTCP:LISTENnetstat -ano | findstr :911On 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 911 — what you actually met is decided by the host, not the registry. If a service is missing here, it belongs in the registry.
contribute an entry