Port 186: KIS Protocol — The Ghost of the Internet's First Search Engine

Port 186 is assigned to KIS (Knowbot Information Service) for both TCP and UDP. It's a ghost port now, reserved for a service that debuted in December 1989 and vanished before most people knew the Internet existed.

What KIS Was

The Knowbot Information Service was a username directory search tool—think of it as WHOIS on steroids. When you queried KIS, it automatically searched multiple Internet user databases (white pages services) simultaneously: the InterNIC, MILNET, MCImail, and the PSI White Pages Pilot Project.¹

One query, multiple databases, automatic results. In 1989, this was revolutionary.

The First Search Engine

KIS debuted in December 1989. The World Wide Web wouldn't launch until 1991. KIS searched users rather than content, but it queried more than a single network for information. By that definition, it might have been the Internet's first search engine.¹

It just searched for people instead of pages.

The CNRI Connection

KIS was operated by the Corporation for National Research Initiatives (CNRI) in Reston, Virginia—an organization founded in 1986 by Robert Kahn, co-inventor of TCP/IP.² Kahn and Vint Cerf were working on digital library research, and the Knowbot project was part of their broader vision for mobile software agents that could operate across networked environments.³

"Knowbot" meant a mobile software agent—a program that could move through the network collecting and storing information to handle distributed tasks.³ KIS was the information service component. Remote-KIS ran on port 185.

How It Worked

Users could access KIS by telnetting to info.cnri.reston.va.us or sol.bucknell.edu.¹ You'd type a name, and KIS would fan out queries to multiple directory services, aggregate the results, and return them to you.

This was 1989. The Internet had maybe 100,000 hosts total. Finding someone's contact information meant knowing which network they were on. KIS automated that search.

Port Assignment

Port 186 appears in RFC 1700 (Assigned Numbers, October 1994) as the official assignment for KIS Protocol, with Ralph Droms listed as the contact.⁴ The assignment covers both TCP and UDP.

By the time RFC 1700 was published, KIS was already fading. The web was taking over. Search engines were learning to index content instead of usernames. Directory services were becoming distributed and decentralized.

Port 186 remained reserved.

Why It Matters

KIS is gone. CNRI moved on to other projects (they later developed the Handle System for persistent digital identifiers). The Knowbot vision of mobile software agents never quite materialized the way Kahn and Cerf imagined.

But port 186 is still there in the IANA registry, carrying the ghost of a service that tried to make the early Internet searchable before anyone knew what search engines would become.

Security Considerations

Port 186 has been exploited by malware in the past.⁵ Since KIS is no longer a legitimate active service, any traffic on port 186 should be investigated. If something is listening on this port on your network, it's either:

1. Legacy infrastructure that someone forgot about
2. Malware using an abandoned port assignment
3. A custom application repurposing the port

Check what's listening:

# Linux/Mac
sudo lsof -i :186
sudo netstat -tulpn | grep :186

# Windows
netstat -ano | findstr :186

If you find unexpected services, investigate immediately.

Related Ports

• Port 185 — Remote-KIS (Remote Knowbot Information Service)
• Port 43 — WHOIS, the simpler single-database predecessor
• Port 389 — LDAP, the successor for directory services

The Truthline

Port 186 carried queries to what might have been the Internet's first search engine. It debuted in December 1989, two years before the web existed. It searched for people instead of pages. And now it's just a reservation in the IANA registry, a placeholder for a service that tried to organize the Internet before anyone knew what the Internet would become.

The Knowbot Information Service is dead. Port 186 is still reserved. That's how the Internet works—the infrastructure persists long after the purpose vanishes.