Port 296 is unassigned. It sits in the well-known ports range (0-1023)—the range where the Internet Assigned Numbers Authority (IANA) assigns port numbers to fundamental protocols—but no service claims it.1
The IANA registry jumps from port 295 (marked "Reserved") directly to port 300 (tacacss/tcp). Port 296 doesn't exist in the official record. It's a gap in the numbering.2
What the Well-Known Range Means
Ports 0 through 1023 are called well-known ports or system ports. These are assigned through rigorous procedures—"IETF Review" or "IESG Approval"—because they're meant for fundamental Internet services.3
This is the range where SSH lives (port 22), where HTTP lived before HTTPS (port 80), where email protocols reside (ports 25, 110, 143, 587, 993, 995). These are the ports that shaped how the Internet works.
Port 296 is in this prestigious range but has no tenant.
Why Ports Go Unassigned
The well-known range has 1,024 possible port numbers. Not all of them are used. Some are reserved for future use. Some were assigned to protocols that died. Some, like 296, were simply never claimed.
The IANA registry is conservative about assignments in this range. Getting a well-known port requires demonstrating that a protocol needs it, that it will be widely deployed, that it serves a fundamental purpose. Port 296 hasn't met that bar for any protocol yet.
What Might Be Using Port 296
Just because port 296 is unassigned doesn't mean nothing will ever listen on it. Any application can bind to any port. Custom software, internal tools, proprietary services—these can use port 296 without official permission.
If you find something listening on port 296, it's likely:
- Custom or proprietary software specific to your network
- A misconfigured service that should be using a different port
- Internal development or testing tools
- Private protocols that don't need or want official registration
How to Check What's Listening
On Linux or macOS:
On Windows:
The first command shows what process is using the port. The second finds the process ID, which you can look up in Task Manager.
Security Considerations
Unassigned ports carry no inherent security risk. They're not targeted by common attacks because there's no standard service to exploit. Port 296 doesn't appear in malware port lists or trojan databases.4
That said, anything listening on an unusual port deserves scrutiny. If you didn't intentionally configure something to use port 296, investigate what's using it and why.
The Gaps in the System
Port 296 is one of many unassigned ports in the well-known range. These gaps serve a purpose: they're potential future homes for protocols we haven't invented yet. They're space held in reserve.
The Internet's port system is finite—only 65,535 ports per transport protocol—but within that constraint, there's room for things we don't know we'll need. Port 296 is that room.
Related Ports
- Port 295 — Reserved by IANA
- Port 300 — tacacss/tcp (Terminal Access Controller Access Control System Security)
- Ports 297-299 — Also unassigned
Frequently Asked Questions
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