Port 621 is commonly used by the macOS Server app for FileMaker Pro sharing. It is also used for HOF (Highly Optimized File) transfers in the HOF protocol.
Ports those registered with IANA are shown as official ports. The same port number may be unofficialy used by various services or applications. The official usage are listed separately below its usage may change from time to time.
Official
Port |
Protocol (TCP/UDP) |
Title |
Description |
Port Type |
Port 621 |
tcp |
escp-ip |
ESCP |
WELL KNOWN PORT |
Port 621 |
udp |
escp-ip |
ESCP |
WELL KNOWN PORT |
UnOfficial
Unofficialy or sometimes with conflict, the same port may be used by different applications.
Port | Protocol (TCP/UDP) | Description |