What This Port Does
Port 2343 belongs to NI Logos, a networking layer built by National Instruments that underlies LabVIEW's Network Shared Variables and Network Streams. If you're seeing activity on this port, you're almost certainly in a lab, factory, or research facility running NI hardware and software.
Logos acts as a service directory. When a LabVIEW application wants to connect to a shared variable on another machine, it first connects to port 2343 to ask: "What port is that variable running on?" Only after getting an answer does it go knock on the actual door. It's a port that finds ports.
Once the lookup is complete, the actual data flows over:
- TCP 2343 — the Logos directory service itself
- UDP 6000–6010 — Network Shared Variable data streams
- TCP 59110+ — additional dynamic service ports
What Is LabVIEW, and Why Does It Need This?
LabVIEW is National Instruments' graphical programming environment, used primarily in science, engineering, and industrial automation. It's how physicists control particle accelerators, how automotive engineers run test benches, how semiconductor fabs coordinate measurement equipment.
Network Shared Variables are one of LabVIEW's mechanisms for passing data between networked machines — sensor readings, control signals, status flags. When you have dozens of machines in a facility all sharing data in real time, you need a consistent way to discover and connect to those data streams. That's what port 2343 provides.
NI Logos is not a standalone install. It ships bundled inside LabVIEW and other NI software products, quietly listening on port 2343 whenever those products are running.
Security Considerations
If you see port 2343 open on a machine that has no business running LabVIEW or NI software, that's worth investigating. While the port itself isn't inherently malicious, some older malware databases flagged it because any open listening port is a potential attack surface, and NI software in exposed environments can be misconfigured.
For industrial systems, the bigger concern is that LabVIEW deployments sometimes end up on networks they shouldn't be reachable from. A LabVIEW server with port 2343 exposed to the public Internet is a misconfiguration — these systems are designed for internal facility networks.1
How to Check What's Listening on This Port
On macOS or Linux:
On Windows:
Then match the PID to a process in Task Manager. If you see lkcitdl.exe or any NI-related process, that's Logos.
To identify the process by name on Windows:
About the Registered Port Range
Port 2343 sits in the registered ports range (1024–49151), maintained by IANA. Unlike well-known ports (0–1023), registered ports don't require elevated privileges to open, and they cover a vast territory — over 48,000 numbers — assigned to specific applications and services by request.
IANA's assignment of 2343 to "nati-logos" means National Instruments formally registered this port for their use. The registration exists but carries no enforcement weight; any application can open any port it wants. The registry just records intent and helps avoid accidental collisions.2
Frequently Asked Questions
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