Port 2628: DICT — The Internet's Forgotten Library

Port 2628 belongs to DICT, the Dictionary Server Protocol. It is officially assigned by IANA to both TCP and UDP, defined by RFC 2229, and represents a specific moment in Internet history: the late 1990s, when idealists were building open, federated knowledge infrastructure before Google made the problem feel solved.

What DICT Does

DICT is a TCP-based query protocol. A client connects to a DICT server, asks for the definition of a word, and the server looks it up across multiple dictionary databases simultaneously — WordNet, the Jargon File, FOLDOC, Webster's 1913, GNU Collaborative International Dictionary of English — and returns results from all of them in a single session.

One connection. Every dictionary. Structured responses.

The protocol is text-based and human-readable, similar to SMTP or FTP in spirit. Commands like DEFINE and MATCH give you definitions or word lookups. The server responds with status codes and plain text. You can pipeline commands, authenticate for restricted databases, and query which dictionaries are available.

Why It Was Built

In the early 1990s, universities ran Webster protocol servers — simple TCP services on port 2627 that let you look up words in a single dictionary. They were modest, useful, and quietly everywhere.

By the mid-1990s they were dying. The Webster servers were going offline faster than new ones appeared, and a new problem had emerged: dozens of freely distributable dictionaries existed on the Internet but had no common access method. Each sat in its own corner, reachable only by its own interface, if it was reachable at all.

In October 1997, Rickard Faith and Bret Martin at the University of North Carolina published RFC 2229. Their goal: replace the dying Webster protocol with something better. One protocol, all the dictionaries, accessible from anywhere.¹

The port number was deliberate. Webster lived on 2627. DICT took 2628 — the next door over.

The Dream, While It Lasted

For a few years, it worked. dict.org ran a public DICT server available to anyone. You could type a command and get definitions from a dozen authoritative sources simultaneously. WordNet gave you semantic relationships. The Jargon File gave you hacker culture. Webster's 1913 gave you the formal definition. FOLDOC gave you the computing angle. All in one query.

This was open knowledge infrastructure. No ads, no tracking, no rate limiting for normal use. Just a protocol and a server, doing what protocols and servers do.

What Killed It

Nothing killed it dramatically. It just became unnecessary.

Google's search index grew to cover every dictionary page. Wikipedia emerged. Google eventually added a dictionary panel directly to search results. The web browser became the universal interface for everything.

DICT required a client. It required knowing the protocol existed. It required caring about the distinction between WordNet and FOLDOC. The web didn't require any of that.

The Ghost That Remains

Port 2628 is still officially assigned. IANA lists it. RFC 2229 is still there.²

More surprisingly: curl still speaks DICT. To this day, you can run:

curl dict://dict.org/d:ephemeral

And if the server is up, you'll get a definition back. The dict:// URL scheme is a named protocol in curl's documentation, sitting alongside https:// and ftp:// like an artifact from a parallel timeline.³

A small number of DICT servers still run. The dictd server package is still maintained in Linux distributions. Someone, somewhere, is still tending this protocol.

What Range This Port Belongs To

Port 2628 sits in the registered port range (1024–49151). These ports are:

• Not reserved for privileged processes (unlike well-known ports below 1024)
• Officially registered with IANA for specific services
• Available for any process to use, but conventionally associated with their registered service

Registered ports are where most application-layer protocols live — databases, custom services, specialized protocols. They're the middle layer of the port numbering system: documented, named, but not locked down.

Checking What's Using This Port

To see if anything is listening on port 2628 on your system:

# Linux/macOS
sudo ss -tlnp | grep 2628
sudo lsof -i :2628

# macOS alternative
netstat -an | grep 2628

# Test a remote DICT server
curl dict://dict.org/d:hello

If you find something unexpected on this port that isn't a DICT server, treat it with the same skepticism you'd apply to anything unfamiliar: figure out what process owns it before assuming it's benign.

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