Port 8891
ddi-tcp-4 and ddi-udp-4 · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | ddi-tcp-4 and ddi-udp-4 |
Frequently asked questions
What is port 8891 used for?
Port 8891 is registered with the IANA for ddi-tcp-4 and ddi-udp-4 (TCP/UDP). Description: Desktop Data TCP 3: NESS application; Desktop Data UDP 3: NESS application.
Is port 8891 a well-known port?
No. Port 8891 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 8891 is open?
Locally on Linux with ss -tulpn | grep ':8891\b', on Windows with netstat -ano | findstr :8891. To test a remote host use Test-NetConnection <host> -Port 8891 in PowerShell or nc -zv <host> 8891 on Linux/macOS.
How do I open port 8891 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 8891/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=8891/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 8891" -Direction Inbound -Protocol TCP -LocalPort 8891 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | ddi-tcp-4 | Desktop Data TCP 3: NESS application |
| UDP | ddi-udp-4 | Desktop Data UDP 3: NESS application |