Port 2829: silkp1 — The Network Flow Collector

What Port 2829 Is

Port 2829 sits in the registered port range (1024–49151). These ports are assigned by IANA on application from software vendors, researchers, or organizations that need a stable, official port number for their tools. They're not reserved for core Internet infrastructure — but they're not random either. Someone asked for this one.¹

Port 2829 was registered as silkp1: the first collection port for SiLK.

SiLK: System for Internet-Level Knowledge

SiLK is a network traffic analysis toolkit developed by the CERT Network Situational Awareness team at Carnegie Mellon University's Software Engineering Institute.² It was built to answer a specific problem: large networks generate more flow data than any human analyst can read. Border routers log billions of connections. SiLK gives security teams tools to store, query, and reason about that data at scale.

The packing system — the part that actually listens and collects — is where port 2829 comes in. The SiLK architecture splits collection infrastructure across multiple ports, and silkp1 is the first of them. The "p1" stands for pack 1.

SiLK is not a consumer product. It runs at the backbone and border of large enterprise networks and ISPs, doing the unglamorous but essential work of turning router telemetry into something analysts can query. Think: "Show me all connections to this IP range between 2am and 4am on Tuesday." That's the problem SiLK solves.³

The IANA Record

The IANA entry for port 2829 lists the service name, description, and assignee all as "silkp1" — three fields, one word, repeated three times.¹ This is not unusual for older registrations where the submitter provided the bare minimum. The port is real and the software is real; the documentation is not.

Port 2829 is registered for both TCP and UDP.

Is Anything Else Using This Port?

Unlikely to show up in consumer environments. SiLK is specialized security research infrastructure — not a protocol you'll find running on home routers, web servers, or cloud instances unless someone has specifically deployed a SiLK collection environment.

If you see traffic on port 2829 and you're not running SiLK, it's worth investigating. Attackers occasionally use registered-but-obscure ports for command-and-control traffic precisely because they don't trigger immediate recognition.

How to Check What's Listening

# Linux/macOS — show what process is bound to port 2829
ss -tlnp | grep 2829
lsof -i :2829

# Windows
netstat -ano | findstr :2829

If something is listening on port 2829 and you didn't put it there, that's the question worth asking.