Port 629 sits in the well-known ports range (0-1023), officially assigned by IANA to a protocol called 3Com AMP3. The assignment is still in the registry. The protocol is not.
What Was 3Com AMP3?
3Com AMP3 (3Com Asset Management Protocol 3) was a network management service developed by 3Com Corporation—once a giant in networking hardware, the company that gave us Ethernet cards, switches, and the Palm Pilot.1 AMP3 ran on both TCP and UDP port 629, handling asset management tasks on corporate networks.2
The protocol appears in Cisco's network classification systems as a recognized service, suggesting it was common enough in the 1990s and early 2000s to warrant detection and traffic shaping.3 But details about how it actually worked—what messages it sent, what problems it solved, who used it—have largely vanished along with 3Com itself.
The Ghost in the Registry
3Com was acquired by Hewlett-Packard in 2010, and HP later absorbed the brand entirely. The AMP3 protocol disappeared from production networks years before that. Yet port 629 remains assigned to "3com-amp3" in IANA's official registry, a permanent placeholder for a service that no longer exists.4
This is what happens to ports when companies die. The IANA registry doesn't delete assignments. It preserves them. So port 629 sits there—officially claimed, practically abandoned, a number that once meant something specific now meaning mostly nothing.
What Actually Uses Port 629 Today?
Almost nothing legitimate. Some security databases flag port 629 as having been used by malware in the past—trojans that picked the port precisely because it's assigned but unused, a quiet corner of the port range where suspicious traffic might go unnoticed.5
If you see traffic on port 629 today, it's probably one of three things:
- Legacy equipment running ancient 3Com software that hasn't been updated since the Bush administration
- Malware using the port opportunistically
- Nothing important at all—random network noise, scanning traffic, misconfigured services
How to Check What's Listening
On Linux or macOS:
On Windows:
If something's there, it's worth investigating. Modern networks shouldn't have anything on 629.
Why This Port Matters (Even Though It Doesn't)
Port 629 matters because it represents a truth about the Internet's infrastructure: nothing ever gets fully deleted. Domain names expire and get re-registered. IP addresses get reassigned. But port numbers? Once allocated, they stay allocated, even when the protocol dies and the company that created it ceases to exist.
The well-known ports range is full of these ghosts—services assigned in the 1980s and 90s that nobody uses anymore but that still occupy their designated numbers. IANA could theoretically reclaim port 629, re-assign it to something modern and useful. But the process for doing that is deliberately slow and cautious, because changing port assignments breaks things in unexpected ways.
So port 629 remains. A number. An assignment. A piece of networking history that most people will never encounter, never need, and never miss.
The Internet has a long memory. Sometimes that means preserving knowledge. Sometimes it just means keeping the tombstones.
หน้านี้มีประโยชน์หรือไม่?