Port 412: Synoptics Trap — A Ghost Port from the Ethernet Wars

What Port 412 Is

Port 412 is officially assigned to "synoptics-trap" (Trap Convention Port) for both TCP and UDP protocols.¹ It was registered by Illan Raab for SynOptics Communications' proprietary network management system.

The port sits in the well-known range (0-1023), which means it required IETF Review for assignment and was considered important enough to warrant protection by the operating system. Ports in this range typically require root/administrator privileges to bind to.

The Company That Owned It

SynOptics Communications was a Santa Clara networking company that existed from 1985 to 1994.² They popularized modular Ethernet hubs and high-speed Ethernet over twisted-pair copper—foundational technologies for modern networks. At their peak in 1993, they pulled in $700 million in annual revenue.

In 1994, SynOptics merged with Wellfleet Communications to form Bay Networks. Bay Networks was later acquired by Nortel in 1998. Nortel collapsed spectacularly in 2009.

The company is gone. The port remains.

What the Port Was For

Port 412 was designated for "Trap Convention Port"—part of SynOptics' network management system. In network management, a "trap" is an unsolicited alert sent from a network device to a monitoring station when something significant happens (link down, authentication failure, temperature warning).

This was SynOptics' proprietary alternative to SNMP traps, which use UDP port 162.³ SNMP (Simple Network Management Protocol) became the de-facto standard for network monitoring by the 1990s. SynOptics' trap system did not.

Why This Port Matters

Port 412 is a fossil. It's assigned to a company that hasn't existed for three decades, for a protocol that was never widely adopted, sitting in the well-known port range where space is precious.

The well-known ports (0-1023) are a finite resource. Every assignment is supposed to matter. New assignments in this range require IETF Review—serious justification.⁴ Yet here sits port 412, reserved forever for a protocol nobody runs.

IANA doesn't reclaim ports. Once assigned, they stay assigned. The registry is append-only history. Port 412 will likely remain "synoptics-trap" until the Internet itself stops using port numbers.

Current Use

Port 412 is not in active use by any mainstream service. If you find something listening on port 412 on your network, it's either:

• Legacy SynOptics equipment (extremely unlikely unless you're running a network archaeology museum)
• A custom application that chose port 412 because it was "available" (not understanding it's actually assigned)
• Malware using an obscure port to avoid detection

To check what's listening on port 412 on your system:

# On Linux/Mac
sudo lsof -i :412
sudo netstat -tulpn | grep :412

# On Windows
netstat -ano | findstr :412

What This Port Carries

Nothing. Port 412 carries the memory of the Ethernet wars of the early 1990s, when competing vendors fought to define how networks would work. SynOptics won some battles (twisted-pair Ethernet became ubiquitous) and lost others (their proprietary management system vanished).

The port is a tombstone in the IANA registry—proof that a company once existed, once built network equipment, once convinced IANA they needed a well-known port for their trap system.

Every time you see an assigned but unused port, you're looking at a decision someone made decades ago that didn't pan out. Port 412 is that decision, frozen in the registry forever.

Related Ports

• Port 161 (UDP): SNMP (Simple Network Management Protocol) - The standard that won
• Port 162 (UDP): SNMP Trap - Where trap messages actually go in modern networks
• Port 705: AgentX - SNMP sub-agent protocol