Port 402 sits in the well-known port range (0-1023), reserved for services assigned by the Internet Assigned Numbers Authority (IANA). According to the official registry, port 402 is assigned to the "Genie Protocol" with Mark Hankin listed as the assignee.1
There's just one problem: there's no evidence the Genie Protocol was ever implemented or used.
The Ghost Protocol
Search for documentation about the Genie Protocol and you'll find nothing. No RFC. No specification. No software that implements it. The IANA registry lists it, but the protocol itself seems to have vanished—if it ever existed at all.
This happens more often than you'd think in the well-known port range. Someone reserves a port number for a protocol they're developing. The protocol never ships, or it ships but nobody uses it, or the company pivots to something else. The reservation remains in the registry, a fossil of intention without implementation.
What Actually Uses Port 402
In the real world, port 402 belongs to Altiris Deployment Solution (later acquired by Symantec, now part of Broadcom). This is enterprise software used to deploy operating system images, push software updates, and manage thousands of computers remotely.2
When an Altiris client boots up, it connects to the deployment server on port 402. The server sends task commands, status updates, and deployment images through this connection. The client listens on this port to receive instructions: "Install this image." "Apply these patches." "Join this domain."
Once the initial connection is established on port 402, the actual file transfers happen over dynamic ports. But port 402 is the handshake, the initial contact point where the client says "I'm here, what do you need me to do?"3
The Security Consideration
Port 402 communication is not encrypted by default. Everything flows in cleartext unless you layer additional security (VPN tunnels, for example). This matters because deployment traffic often includes sensitive information: domain credentials, configuration data, software packages.
If port 402 is open on your network perimeter and you're not running Altiris, investigate. The port has been used by malware in the past, though no specific current threats are widely associated with it.4
Well-Known Ports and Unassigned Space
Port 402 illustrates something important about how the Internet actually works versus how we think it works. The well-known port range was supposed to be carefully managed—official assignments for standardized protocols. But reality is messier.
Vendors need port numbers. Sometimes they request official assignments and get a number that nobody remembers. Sometimes they just pick a number in the registered range (1024-49151) and start using it. Sometimes they pick a well-known port that has an official assignment but no actual usage.
Port 402 got an official assignment that evaporated, then got claimed by actual software that thousands of organizations depend on. The registry and reality diverged, and reality won.
Checking What's Listening
To see if something is listening on port 402 on your system:
Linux/macOS:
Windows:
If you see a process listening and you're not running Altiris Deployment Solution, investigate what it is and why it's there.
The Gap Between Documentation and Reality
Port 402 is a reminder that the official registry is not the map of the territory. It's a record of intentions, some of which materialized and some of which didn't. The Genie Protocol got its number and disappeared. Altiris needed a port and found one that worked.
The Internet doesn't wait for perfect documentation. It uses what works and moves on.
이 페이지가 도움이 되었나요?