Port 212: ANET — The Protocol That Forgot Itself

Port 212 sits in the well-known ports range (0-1023), officially assigned by IANA to a service called "anet" with the description "ATEXSSTR." The contact is listed as Jim Taylor. And that's where the trail goes cold.¹

The Ghost in the Registry

Port 212 is officially assigned. It's registered for both TCP and UDP. It has a service name, a description, and a contact person. But if you search for what ATEXSSTR actually does, you'll find nothing. No RFC. No documentation. No implementation guides. No active services using it.

The protocol exists in the registry but not in the world.

This is genuinely strange: the Internet Archive remembers every version of every webpage, but it doesn't remember what ATEXSSTR was for. The port assignment survives while the protocol itself has been erased from institutional memory. It's digital archaeology in reverse—the catalog entry outliving the artifact.

What "Well-Known" Means

Port 212 falls in the System Ports range (0-1023), which means:

• Requires Privileges — Only root or administrator accounts can bind services to these ports on most systems
• IANA Assigned — These ports go through formal IANA procedures (IETF Review or IESG Approval)
• Historical Weight — Many assignments date back decades to protocols that mattered when the Internet was young

Port 212 has this official status, this weight of history, pointing to a protocol that left no trace except its name in the registry.

What Might Be Listening

Even though ATEXSSTR has vanished, other things might use port 212:

Check what's listening:

# On Linux/Mac:
sudo lsof -i :212
sudo netstat -tulpn | grep :212

# On Windows:
netstat -ano | findstr :212

Scan a remote host:

nmap -p 212 target-host

If something responds, it's probably not ATEXSSTR. Some sources mention port 212 being associated with IAX (Inter-Asterisk eXchange), a VoIP protocol used by Asterisk telephony systems, though this appears to be an unofficial use that overlaps with the official assignment.²

The same sources also flag port 212 as having been exploited by trojans in the past—a reminder that unused or forgotten ports can become convenient hiding places for malicious software.²

Why Forgotten Ports Matter

Port 212 teaches something important about the Internet's infrastructure:

The registry is not self-documenting. A port can be officially assigned, properly registered, and completely mysterious. The name "ATEXSSTR" tells you nothing if the people who named it didn't write it down.

Assignments outlive protocols. The Internet moves fast, but the port registry moves slowly. Protocols die, companies disappear, contact information goes stale—but the port assignment remains, a permanent record of something that no longer exists.

The gaps are as important as the assignments. When you scan a network and find port 212 open, you're not finding ATEXSSTR. You're finding something else using a port that was assigned to a ghost. That's useful information. It tells you someone chose this port specifically because it's registered but forgotten—either for legitimate reasons (avoiding conflicts) or suspicious ones (hiding in plain sight).

The Honest Truth

Port 212 is officially assigned to ATEXSSTR. If you need to know what ATEXSSTR actually did, what problem it solved, who created it, or why it mattered—I can't tell you. Nobody can. The protocol forgot itself.

What remains is a line in the IANA registry, a service name with no service, and a lesson about how the Internet's memory works: some things are cataloged forever, even when we've forgotten what they were for.

How to Check Port 212

If you find port 212 open on a system:

# Check what's bound to the port
sudo ss -tulpn | grep :212

# Try connecting to see what responds
telnet target-host 212
nc -v target-host 212

Whatever answers probably isn't ATEXSSTR. But it's using a port that officially belongs to a protocol that vanished, and that's worth investigating.