TCPRegistered PortFirewall: Usually Closed
6665

IRC (alternate)

What is Port 6665?

Port 6665 is part of the standard IRC port range 6660-6669. IRC has been using this extended port range since the 1990s when the protocol moved away from the IANA-assigned port 194 due to privilege requirements on Unix systems. Many IRC clients default to trying ports 6665-6667 when connecting to an IRC network. Some IRC networks use different ports for different connection types — for instance, some may reserve certain ports for registered users while keeping others open for guest access. Port 6665 provides standard unencrypted IRC connectivity.

Common Uses

  • IRC server connections
  • Standard IRC client connection port
  • IRC network connectivity option
  • Developer community real-time chat

Technical Details

Port Number6665
ProtocolTCP
CategoryRegistered
Service NameIRC (alternate)
Default FirewallUsually Closed
Port Test Commands

Copy-paste commands to check port 6665 (IRC (alternate)) from your terminal

Test connectivity

Netcat (nc)Check if TCP port is reachable
nc -zv example.com 6665
curl (HTTP)Test HTTP response on this port
curl -v --max-time 5 http://example.com:6665/
TelnetBasic TCP port connectivity check
telnet example.com 6665
nmapScan port 6665 with service detection
nmap -p 6665 -sV example.com
Bash /dev/tcpPure bash TCP check (no extra tools needed)
(echo > /dev/tcp/example.com/6665) 2>/dev/null && echo "open" || echo "closed"

Open port in firewall

UFW (Ubuntu / Debian)
sudo ufw allow 6665/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 6665 -j ACCEPT
firewalld (RHEL / CentOS)
sudo firewall-cmd --permanent --add-port=6665/tcp && sudo firewall-cmd --reload

Security Considerations

!

Unencrypted IRC connection. Prefer TLS port 6697. Apply network monitoring for unauthorized IRC activity.

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