Port 2793: initlsmsad — Registered in Name Only

What Port 2793 Is

Port 2793 sits in the registered ports range (1024–49151), the middle tier of the port number system. Unlike the well-known ports below 1024 — where SSH, HTTP, and DNS live with decades of documentation and RFCs — registered ports are claimed by organizations and vendors for their own applications, sometimes with careful documentation, sometimes not.

IANA lists port 2793 under the name initlsmsad for both TCP and UDP.¹ That name is, generously, opaque. It may be an abbreviation for something involving initialization ("init"), possibly a messaging or session component ("lsm"), and possibly a security association database ("sad") — but this is speculation. No RFC was ever filed. No vendor has publicly documented this service. The registration exists; the explanation does not.

What the Name Might Mean

Breaking it apart phonetically: init-lsm-sad. In networking contexts, "SAD" (Security Association Database) is a real term from IPsec. "LSM" appears in Linux Security Modules and various enterprise middleware products. "Init" is universal. But connecting these into something that explains what port 2793 actually does, for whom, and when — that trail goes cold immediately.

If you're seeing this port active on a machine you manage, it is almost certainly not this registration causing it. It's something else using an available number.

What You're More Likely to See

The 2700–2800 range has been loosely associated with KnowShowGo P2P in some references.² Various applications pick unused registered ports opportunistically. If port 2793 shows up in your environment, the process listening on it is the only reliable source of truth.

How to Check What's Listening

On Linux or macOS:

sudo ss -tlnp | grep 2793
# or
sudo lsof -i :2793

On Windows:

netstat -ano | findstr :2793

The process name in the output tells you far more than any port database can.

Why Unassigned Ports Matter

The registered ports range has room for roughly 48,000 entries. Many of those slots hold registrations like this one — names filed years ago, applications long since discontinued or never released, vendors who moved on. These ghost registrations aren't harmful. They're just the sediment of the Internet's history: evidence that someone, once, had a plan.

The practical consequence is that any software needing a predictable port can pick a registered number that isn't actively defended by a living protocol. Port 2793 is one of many such numbers — not unknown enough to be ephemeral, not active enough to mean anything specific.