Port 3071: xplat-replicate — Registered, Invisible

What Port 3071 Is

Port 3071 sits in the registered port range (1024–49151), the middle tier of the port numbering system. IANA assigned it in August 2017 to NetApp, Inc., under the service name xplat-replicate, described as a "crossplatform replication protocol." ¹

UDP at this port number is reserved; TCP is the assigned transport.

The Range It Lives In

The registered port range exists for applications and services that want a stable, predictable port number without needing the historic privilege of a well-known port (0–1023). Companies and open-source projects apply to IANA, pay nothing, and receive a port number to call their own.

The tradeoff: IANA records the assignment but doesn't enforce it. Nothing stops software from using any port it wants. The registry is a directory, not a contract.

What xplat-replicate Actually Does

Unclear. NetApp registered the port, but there's no public RFC, no developer documentation, and no forum threads about it. The name suggests internal data replication across platforms — consistent with NetApp's storage and ONTAP product lines — but the protocol details aren't publicly specified. ²

This isn't unusual. Many registered ports are for internal enterprise protocols that were never intended to be public-facing. The registration secures the number; the protocol stays proprietary.

Is Anything Running on It?

Almost certainly not on a typical machine. You can check what's listening on your system:

macOS / Linux:

sudo lsof -i :3071

Windows:

netstat -ano | findstr :3071

If nothing comes back, nothing is using it. That's the expected result for the vast majority of systems.

Why Registered Ports Like This Matter

The registered range is where the Internet's unglamorous middle class lives. Not the famous ports (80, 443, 22) and not the chaos of ephemeral ports (49152–65535). Just tens of thousands of named, claimed numbers — many of them assigned for software you'll never run.

They matter because the alternative is worse. Without registration, two applications on the same machine would choose port numbers by convention or accident and collide. The registry is a shared agreement that port 3071, at least in theory, belongs to one thing.

Port 3071 is a placeholder that became a fact. Registered, quiet, doing whatever NetApp replication needs done — somewhere, on someone's storage cluster, almost certainly not yours.