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Port 4131 (stars)

IANA assigns port 4131 to stars: Global Maintech Stars.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
stars TCP Global Maintech Stars Harry Goldschmitt 2 -
stars UDP Global Maintech Stars Harry Goldschmitt 2 -

Registry dates for this port: registered 2007-06.

Check what is listening on port 4131

Linux: is anything listening on TCP 4131?
sudo ss -tlnp 'sport = :4131'
Linux: UDP 4131
sudo ss -ulnp 'sport = :4131'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4131
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4131 '
Windows (Command Prompt)
netstat -ano | findstr :4131
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4131 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4131
From Windows
Test-NetConnection HOST -Port 4131
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4131

Block port 4131 in the firewall

ufw
sudo ufw deny 4131/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4131 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4131 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4131' -Direction Inbound -Protocol TCP -LocalPort 4131 -Action Block
ufw
sudo ufw deny 4131/udp
iptables
sudo iptables -A INPUT -p udp --dport 4131 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4131 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4131' -Direction Inbound -Protocol UDP -LocalPort 4131 -Action Block

Related ports

4129nuauth4130fronet4132nuts-dem, nuts_dem4133nuts-bootp, nuts_bootp

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