Port 1640

cert-responder · TCP/UDP

RangeRegistered port (1024–49151)
ProtocolTCP/UDP
Servicecert-responder

Frequently asked questions

What is port 1640 used for?

Port 1640 is registered with the IANA for cert-responder (TCP/UDP). Description: cert-responder.

Is port 1640 a well-known port?

No. Port 1640 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.

How do I check whether port 1640 is open?

Locally on Linux with ss -tulpn | grep ':1640\b', on Windows with netstat -ano | findstr :1640. To test a remote host use Test-NetConnection <host> -Port 1640 in PowerShell or nc -zv <host> 1640 on Linux/macOS.

How do I open port 1640 in the firewall?

Ubuntu/Debian (ufw): sudo ufw allow 1640/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=1640/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 1640" -Direction Inbound -Protocol TCP -LocalPort 1640 -Action Allow.

IANA registry entries

ProtocolServiceDescription (IANA)
TCPcert-respondercert-responder
UDPcert-respondercert-responder

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