Port 3570: mccwebsvr-port — A Registered Port with No Footprint

What Port 3570 Is

Port 3570 lives in the registered port range (1024–49151), the middle tier of the port numbering system. Unlike the well-known ports below 1024 — where SSH, HTTP, and DNS have lived for decades — the registered range is where organizations and vendors claim ports for their own applications.

The IANA registry lists port 3570 as mccwebsvr-port: an entry attributed to "MCC Web Server Port." That's the entirety of what the registry tells you. No RFC. No specification. No company name that resolves to anything still operating. The registration exists; the software, if it was ever widely deployed, left no trace.

This is not unusual. The registered range contains thousands of entries like this — claimed ports from products that were discontinued, companies that were acquired, or projects that never shipped.

What the Registered Range Means

When you see a port in the 1024–49151 range, it tells you something specific: this port is not reserved by the operating system (those are below 1024), and it's not ephemeral (those are above 49151). It's the middle ground — ports that applications claim for their own persistent use.

Any application can bind to a registered port without special privileges on most systems. That makes the range both useful and noisy. Legitimate software uses it, malware uses it, and development servers use it. When you encounter an open registered port on a host, the question is never "what's supposed to be there" — it's "what's actually there."

Checking What's on This Port

If port 3570 shows up in a scan or firewall log, identify it directly:

On Linux/macOS:

# See what process is listening on port 3570
ss -tlnp | grep 3570
# or
lsof -i :3570

On Windows:

netstat -ano | findstr :3570
# Then look up the PID:
tasklist | findstr <PID>

With nmap (from another host):

nmap -sV -p 3570 <target-host>

The -sV flag tells nmap to probe the port and attempt to identify the service — which will tell you more than the port number ever could.

Why Unassigned-in-Practice Ports Matter

The gap between "IANA registered" and "actually used" is where confusion lives. Firewall rules sometimes reference IANA names. Security scanners flag ports by registry status. But a registration from 2003 for software nobody runs tells you nothing about what's listening on that port today.

If you find port 3570 open on a machine you manage and you didn't put it there, find out what's using it before you decide whether to allow or block it. The registry offers no help here. The process list will.