Port 1775: vdab — A Registered Port Nobody Uses

What Port 1775 Is

Port 1775 sits in the registered port range (1024–49151). These ports are assigned by IANA upon application — a person or organization submits a request, IANA records it, and the port gets a name. Unlike the well-known ports below 1024, registered ports don't require elevated privileges to bind, and their assigned services aren't always in active use.

Port 1775 was registered on April 23, 2014 for a service called vdab — described as "data interchange between visual processing containers." TCP is assigned; UDP is reserved.

That is the entirety of what IANA knows. ¹

The Protocol That Isn't

"Visual processing containers" sounds like it could be something — perhaps a video pipeline tool, a media processing framework, a container orchestration layer for GPU workloads. But there is no RFC, no public implementation, no GitHub repository, no documentation anywhere that explains what vdab actually does or who registered it.

This is not unusual. The registered port range contains thousands of names like this: plausible-sounding, quietly registered, and then abandoned or kept entirely internal to one organization's private infrastructure. The IANA registry is not a directory of living protocols. It is a reservation system, and reservations often go unfilled.

Scanning Activity

Despite being a quiet port, 1775 does receive unsolicited probes — scanners sweeping registered port ranges looking for anything that responds. ² This is background noise on the Internet, not evidence that vdab is running anywhere. Scanners don't know what's on a port; they knock and listen.

What Might Actually Be on Port 1775

If you see traffic on port 1775 on your own network, it is almost certainly one of:

• Proprietary internal software that chose this port informally
• A misconfigured service that wandered into this range
• Port scanning traffic from external sources probing your network

It is unlikely to be vdab, whatever vdab was meant to be.

How to Check What's Listening

If port 1775 is open on a machine you control:

# Linux/macOS
sudo ss -tlnp | grep 1775
sudo lsof -i :1775

# Windows
netstat -ano | findstr :1775

The output will show the process ID and name bound to the port. That's your answer — not the IANA registry.

Why Unassigned and Unused Ports Matter

The registered port range exists to prevent collisions: if two applications both want port 1775, one of them has to move. The registration system gives organizations a way to stake a claim. But claiming a port and building a protocol are separate acts, and many ports have seen only the first.

Unassigned and abandoned registered ports are also the ports that attackers and malware authors reach for when they want a port that sounds legitimate but won't trigger "why is something on port 22?" alerts. An unfamiliar port number is not evidence of wrongdoing, but it is a reason to look twice.