Port 2941: SM-PAS-4 — A Name Without a Story

Port 2941 sits in the registered port range (1024-49151) — the middle tier of the port numbering system, where organizations once applied to IANA for an official reservation. Unlike well-known ports below 1024, registered ports don't require root privileges to bind, and unlike ephemeral ports above 49151, they're meant to represent stable, named services.

Port 2941 has a name: SM-PAS-4.

That's where the information ends.

The SM-PAS block

IANA's registry shows five consecutive ports assigned to a series:

No RFC documents these ports. No company has publicly claimed them. No protocol specification exists in any accessible archive. The registrations appear to be from an era (likely late 1990s or early 2000s) when IANA's process for registered ports was informal — organizations could request a block without publishing any documentation.

This happens more than you'd expect. Many registered port numbers are "ghost registrations": names in the ledger, nothing behind the door.

What this range means

The registered port range exists because not every protocol needs to be a global standard. Companies, research institutions, and projects could reserve numbers to avoid collisions with other private software. The idea was coordination, not necessarily publication.

Over time, IANA tightened the requirements. Today, a new registered port requires a documented justification. But the old registrations remain — including SM-PAS-1 through SM-PAS-5, whatever they were meant for.

What you'll find on port 2941 in practice

Almost certainly nothing, unless software you've installed chose it for a private reason. Because this port has no widely-used service, it's occasionally picked up by:

• Local development tools selecting ports in the 2900-3000 range
• Enterprise software with hardcoded private port assignments
• Security scanners flagging it simply because it's open

How to check what's listening on this port

macOS / Linux:

lsof -i :2941

Linux (alternative):

ss -tlnp | grep 2941

Windows:

netstat -ano | findstr :2941

If nothing is listening, you'll get no output. If something is, the process name will tell you more than the port number ever could.

Why ghost registrations matter

Most port scanning tools and firewall rules work from the registered port list. A port with an official-sounding name like "SM-PAS-4" might be treated differently than a truly unassigned port — allowed through rules that shouldn't allow it, or flagged as suspicious when it shouldn't be.

The honest answer about port 2941: it has a name, no one knows what that name means, and you almost certainly don't need it open.