Service Name: cableport-ax
Port Number: 282
Transport Protocols: TCP and UDP
Status: Officially Assigned (IANA)
What Port 282 Is
Port 282 is officially registered with IANA as "cableport-ax"—short for Cable Port A/X.1 It sits in the well-known ports range (0-1023), which means it was assigned through formal IETF or IESG approval processes. The registration covers both TCP and UDP protocols.
And that's where the trail goes cold.
The Mystery of Cable Port A/X
No RFC defines Cable Port A/X. No documentation explains what the protocol does. No implementation can be found in modern systems. The name suggests something related to cable television infrastructure, but searches for "cable port ax" or "cableport-ax protocol" turn up nothing but port databases repeating the same three words: Cable Port A/X.
Cisco's NBAR (Network-Based Application Recognition) protocol library acknowledges the port exists2—it lists cableport-ax as using TCP and UDP port 282, supporting IPv4 and IPv6, categorized under "other." That's recognition without explanation.
Whatever Cable Port A/X was supposed to be, it never became anything people actually used.
Why This Matters
Port 282 is a fossil. It's proof that not every officially assigned port becomes part of the Internet's working infrastructure. Someone once thought this protocol mattered enough to request an IANA assignment. The request was approved. The port was documented in the official registry. And then... nothing.
The well-known ports range is supposed to be reserved for fundamental Internet services—the protocols that millions of systems depend on. Most ports in this range carry that weight: SSH on 22, HTTP on 80, HTTPS on 443. But scattered throughout are ports like 282: officially assigned, technically legitimate, practically unused.
These ghost ports are reminders that the Internet isn't just made of working systems. It's also made of abandoned plans, forgotten protocols, and ideas that never found their audience.
Unofficial Uses
Port 282 has occasionally been flagged in security databases as associated with malware or trojans,3 though this doesn't mean the port itself is malicious. Unassigned or rarely-used ports are attractive to malware authors precisely because legitimate software doesn't monitor them. An obscure registered port makes for good camouflage.
No current widespread legitimate use of port 282 can be documented.
How to Check Port 282
To see if anything is listening on port 282 on your system:
Linux/Mac:
Windows:
If you find something listening on port 282, you should investigate what it is. Legitimate use would be unusual.4
Well-Known Ports and IANA
Port 282 belongs to the System Ports range (0-1023), also called Well-Known Ports.5 This range is managed by the Internet Assigned Numbers Authority (IANA), which assigns ports through formal procedures documented in RFC 6335.6
Getting a port assigned in this range requires either IETF Review or IESG Approval. The process exists to ensure that scarce low-numbered ports go to protocols that genuinely need them—protocols expected to become fundamental Internet services.
Port 282 went through that process. Someone believed in Cable Port A/X enough to request official assignment. IANA believed in it enough to grant the request. And then the protocol vanished, leaving only its number behind.
The Lesson
The Internet's port number space tells two stories. The first story is about working systems: protocols that succeeded, services that scaled, infrastructure that endures. The second story is about everything else—the protocols that didn't catch on, the services nobody needed, the infrastructure that was never built.
Port 282 belongs to that second story. It's officially assigned. It's properly documented. It follows all the rules. And it carries nothing, because there was never anything to carry.
That's not a failure of the system. It's proof that the system allows for experiments that don't work out. Some ports become SSH. Some ports become Cable Port A/X. Both are part of how the Internet grows—not just through successes, but through attempts.
Related Ports
- Port 80 — HTTP, a well-known port that actually gets used
- Port 443 — HTTPS, another well-known port in constant use
- Ports 272-279 — The neighborhood around port 282, mostly unassigned or obscure
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