Port 403
decap · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | decap |
Frequently asked questions
What is port 403 used for?
Port 403 is registered with the IANA for decap (TCP/UDP). Description: decap.
Is port 403 a well-known port?
Yes. Port 403 is in the range 0–1023 (system or well-known ports). On Linux and macOS only privileged processes may bind to these ports.
How do I check whether port 403 is open?
Locally on Linux with ss -tulpn | grep ':403\b', on Windows with netstat -ano | findstr :403. To test a remote host use Test-NetConnection <host> -Port 403 in PowerShell or nc -zv <host> 403 on Linux/macOS.
How do I open port 403 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 403/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=403/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 403" -Direction Inbound -Protocol TCP -LocalPort 403 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | decap | decap |
| UDP | decap | decap |