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Port 9889 (gt-proxy)

IANA assigns port 9889 to gt-proxy: Port for Cable network related data proxy or repeater.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
gt-proxy TCP Port for Cable network related data proxy or repeater Dawei Qi -
gt-proxy UDP Port for Cable network related data proxy or repeater Dawei Qi -

Registry dates for this port: registered 2010-07-07.

Check what is listening on port 9889

Linux: is anything listening on TCP 9889?
sudo ss -tlnp 'sport = :9889'
Linux: UDP 9889
sudo ss -ulnp 'sport = :9889'
Linux / macOS: which process owns the port
sudo lsof -nP -i :9889
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':9889 '
Windows (Command Prompt)
netstat -ano | findstr :9889
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 9889 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 9889
From Windows
Test-NetConnection HOST -Port 9889
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 9889

Block port 9889 in the firewall

ufw
sudo ufw deny 9889/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 9889 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 9889 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 9889' -Direction Inbound -Protocol TCP -LocalPort 9889 -Action Block
ufw
sudo ufw deny 9889/udp
iptables
sudo iptables -A INPUT -p udp --dport 9889 -j DROP
nftables
sudo nft add rule inet filter input udp dport 9889 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 9889' -Direction Inbound -Protocol UDP -LocalPort 9889 -Action Block

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All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.