IRC (alternate)
What is Port 6664?
Port 6664 is part of the 6660-6669 IRC port range. IRC servers commonly listen on the entire range to maximize client connectivity options. While ports 6667 (unencrypted) and 6697 (TLS) are the most commonly used, having additional ports available ensures users can connect even with partial port blocking. Some IRC servers assign specific port ranges for different purposes — for example, regular users on some ports and server-to-server links on others. Port 6664 functions identically to other unencrypted IRC ports, providing full IRC protocol access for messaging, channel participation, and file transfers.
Common Uses
- IRC server connections
- Additional IRC connection port
- IRC network connectivity
- Chat client connections
Technical Details
Copy-paste commands to check port 6664 (IRC (alternate)) from your terminal
Test connectivity
nc -zv example.com 6664
curl -v --max-time 5 http://example.com:6664/
telnet example.com 6664
nmap -p 6664 -sV example.com
(echo > /dev/tcp/example.com/6664) 2>/dev/null && echo "open" || echo "closed"
Open port in firewall
sudo ufw allow 6664/tcp
sudo iptables -A INPUT -p tcp --dport 6664 -j ACCEPT
sudo firewall-cmd --permanent --add-port=6664/tcp && sudo firewall-cmd --reload
Security Considerations
No encryption. Always prefer port 6697 with TLS. IRC ports should be blocked in environments where IRC is not authorized.
Popular Ports Reference
The most commonly used and referenced network ports