# WHATPORT(6667)

## NAME

port 6667 — IRC — The default plaintext IRC port — where clients connect to chat networks without TLS.

Protocol: TCP  
IANA registry

## DESCRIPTION

An IRC client opens 6667, sends NICK and USER, and the server answers with a numeric welcome burst and the MOTD; from there everything is line-based text terminated by CRLF, as defined in RFC 1459 and its successors. It is the default port in essentially every IRC client, inside IANA's 6665-6669 ircu block, and RFC 7194 names 6697 as its TLS counterpart. It still shows up on scans of chat networks, of bouncers, and of IRC-controlled malware that never moved off the classic port.

## EXPOSURE

**Expose with care.** Everything is cleartext, including the password you send to NickServ. Fine for a public chat server that offers TLS on 6697 alongside; never the right choice for anything private.

## CHECK

```sh
printf 'QUIT\r\n' | nc -v -w 5 TARGET 6667
```

## SEE ALSO

- spec — [RFC 1459 — Internet Relay Chat Protocol](https://www.rfc-editor.org/rfc/rfc1459.html) (rfc-editor.org)
- spec — [RFC 7194 — Default Port for Internet Relay Chat (IRC) via TLS/SSL](https://www.rfc-editor.org/rfc/rfc7194.html) (rfc-editor.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry — 6665-6669 (ircu)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=6667) (iana.org)
- source — [ircu2 — Undernet IRC Daemon](https://github.com/UndernetIRC/ircu2) (github.com)

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HTML: <https://whatport.net/6667/> · JSON: <https://whatport.net/6667.json> · full dataset: <https://whatport.net/ports.json>