The Registered Port Range
Port 2211 sits in the registered port range (1024–49151). This is the middle tier of the port system:
- Well-known ports (0–1023): Reserved for core Internet protocols — HTTP, DNS, SSH, SMTP. Requires root/admin to bind.
- Registered ports (1024–49151): Available for applications to register with IANA. No root required to use.
- Dynamic/ephemeral ports (49152–65535): Temporary ports assigned by the OS for outgoing connections.
IANA has not assigned port 2211 to any official service. 1 In the registry, it simply reads: unassigned.
But "unassigned" doesn't always mean "unused."
What Actually Uses Port 2211
Port 2211 is the Internet gateway for EMWIN — the Emergency Managers Weather Information Network.
EMWIN is a free data service run by NOAA's National Weather Service. It broadcasts weather products in near real time: tornado warnings, hurricane watches, flash flood advisories, winter storm alerts. Everything the NWS issues goes into the stream. Emergency managers, government agencies, and weather enthusiasts receive it within 5–20 seconds of issuance. 2
The original delivery method was satellite. NOAA uplinks the data to the GOES weather satellites from Wallops Island, Virginia; receivers on the ground pick it up directly. No Internet required, no subscription, no fee.
Someone eventually built an Internet relay — for the people without a satellite dish. That relay server listens on port 2211. The community adopted it. Now emwin.weathermessage.com:2211 is the standard address for software that wants to pull EMWIN data over TCP. 3
It's not an RFC. IANA didn't bless it. But if your software speaks EMWIN over the Internet, it connects to port 2211. That's how informal standards work: someone makes a choice, it propagates, and eventually the choice becomes the convention.
Who Listens to This Port
Emergency operations centers. Ham radio operators who run EMWIN relay nodes. Weather hobbyists. Software like WeatherMessage connects to port 2211 and decodes the stream into local alerts. During a severe weather event, these systems receive the warning the moment NWS issues it.
It's a quiet port doing serious work.
If You Find Port 2211 Open on a System
It's almost certainly not EMWIN unless the machine is intentionally running weather software. To find out what's actually listening:
Linux/macOS:
Windows:
The process ID from those commands will tell you what's actually bound to the port.
Why Unassigned Ports Matter
The IANA registry is the phone book of the Internet — but like any phone book, it's incomplete. Applications pick ports for their own reasons: historical accident, internal convention, the developer's preference. Over time, some of those choices calcify into de facto standards.
Port 2211 is a small example of how the real Internet works alongside the official one. The registry says "unassigned." NOAA's weather relay says "connect here." Thousands of systems connect here. The gap between the two is where much of the actual Internet lives.
آیا دا پاڼه ګټوره وه؟