Port 3412: xmlBlaster — An Official Port for a Forgotten Middleware

What Port 3412 Is

Port 3412 is a registered port, officially assigned by the Internet Assigned Numbers Authority (IANA) to xmlBlaster, an open-source publish/subscribe messaging middleware. The registration dates to February 2002.¹

Despite being listed as "unassigned" in some port databases, IANA records confirm the assignment. The discrepancy likely reflects data lag in third-party databases, or the fact that xmlBlaster never achieved widespread adoption.

What xmlBlaster Was

xmlBlaster was a message-oriented middleware (MOM) server that let software components exchange messages using XML as the message format. Publishers would send XML messages to the server; subscribers would receive them. Topics could be described in XML and queried with XPath.

It supported a notable range of transport protocols for its era: CORBA, XML-RPC, SOCKET, RMI, and IIOP. Client libraries existed for Java, C, C++, Python, Perl, PHP, VB.NET, and C#.

Port 3412 served as its default bootstrap port for the built-in HTTP server, allowing clients to connect and negotiate their preferred protocol.²

Why You're Probably Not Running It

xmlBlaster emerged in an era before modern messaging systems like RabbitMQ (2007), Apache Kafka (2011), or NATS dominated the space. XML was the lingua franca of enterprise integration. By the time lighter, faster alternatives arrived, xmlBlaster never crossed the adoption threshold that turns a project into infrastructure.

The GitHub repository still exists.³ The last meaningful activity is years old. Port 3412 remains registered in its name — official paperwork for a project most engineers today have never heard of.

The Registered Port Range

Port 3412 sits in the registered port range (1024–49151). Ports in this range:

• Require IANA registration, but enforcement is minimal
• Are not restricted by operating systems (unlike well-known ports 0–1023, which require root/admin privileges to bind)
• Can be used by any process on any machine — the registration is a courtesy reservation, not a lock

This means if something is listening on port 3412 on your system, it is almost certainly not xmlBlaster.

What Might Actually Be on Port 3412

If you see traffic on port 3412 in the wild, the likely candidates are:

• Custom internal applications that picked a port from the registered range without checking IANA
• Development servers using the port temporarily
• Malware or scanning tools probing registered ports during reconnaissance

No significant unofficial use has been documented for this port.⁴

How to Check What's Listening

# On Linux/macOS
ss -tlnp | grep 3412
lsof -i :3412

# On Windows
netstat -ano | findstr :3412

The PID returned can be cross-referenced against your process list to identify the owner.