Port 3666

eserver-pap · TCP/UDP

RangeRegistered port (1024–49151)
ProtocolTCP/UDP
Serviceeserver-pap
Registered2003-01

Frequently asked questions

What is port 3666 used for?

Port 3666 is registered with the IANA for eserver-pap (TCP/UDP). Description: IBM eServer PAP; IBM EServer PAP.

Is port 3666 a well-known port?

No. Port 3666 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.

How do I check whether port 3666 is open?

Locally on Linux with ss -tulpn | grep ':3666\b', on Windows with netstat -ano | findstr :3666. To test a remote host use Test-NetConnection <host> -Port 3666 in PowerShell or nc -zv <host> 3666 on Linux/macOS.

How do I open port 3666 in the firewall?

Ubuntu/Debian (ufw): sudo ufw allow 3666/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=3666/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 3666" -Direction Inbound -Protocol TCP -LocalPort 3666 -Action Allow.

IANA registry entries

ProtocolServiceDescription (IANA)
TCPeserver-papIBM eServer PAP
UDPeserver-papIBM EServer PAP

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