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Port 3912 (gbmt-stars)

IANA assigns port 3912 to gbmt-stars: Global Maintech Stars.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
gbmt-stars TCP Global Maintech Stars Harry Goldschmitt -
gbmt-stars UDP Global Maintech Stars Harry Goldschmitt -

Registry dates for this port: registered 2003-11.

Check what is listening on port 3912

Linux: is anything listening on TCP 3912?
sudo ss -tlnp 'sport = :3912'
Linux: UDP 3912
sudo ss -ulnp 'sport = :3912'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3912
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3912 '
Windows (Command Prompt)
netstat -ano | findstr :3912
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3912 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3912
From Windows
Test-NetConnection HOST -Port 3912
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3912

Block port 3912 in the firewall

ufw
sudo ufw deny 3912/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3912 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3912 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3912' -Direction Inbound -Protocol TCP -LocalPort 3912 -Action Block
ufw
sudo ufw deny 3912/udp
iptables
sudo iptables -A INPUT -p udp --dport 3912 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3912 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3912' -Direction Inbound -Protocol UDP -LocalPort 3912 -Action Block

Related ports

3910prnrequest3911prnstatus3913listcrt-port3914listcrt-port-2

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