Port 3857
trap-port · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | trap-port |
| Registered | 2003-08 |
Frequently asked questions
What is port 3857 used for?
Port 3857 is registered with the IANA for trap-port (TCP/UDP). Description: Trap Port.
Is port 3857 a well-known port?
No. Port 3857 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 3857 is open?
Locally on Linux with ss -tulpn | grep ':3857\b', on Windows with netstat -ano | findstr :3857. To test a remote host use Test-NetConnection <host> -Port 3857 in PowerShell or nc -zv <host> 3857 on Linux/macOS.
How do I open port 3857 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 3857/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=3857/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 3857" -Direction Inbound -Protocol TCP -LocalPort 3857 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | trap-port | Trap Port |
| UDP | trap-port | Trap Port |