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Port 3641 (netplay-port2)

IANA assigns port 3641 to netplay-port2: Netplay Port 2.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
netplay-port2 TCP Netplay Port 2 Predrag Filipovic -
netplay-port2 UDP Netplay Port 2 Predrag Filipovic -

Registry dates for this port: registered 2002-11.

Check what is listening on port 3641

Linux: is anything listening on TCP 3641?
sudo ss -tlnp 'sport = :3641'
Linux: UDP 3641
sudo ss -ulnp 'sport = :3641'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3641
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3641 '
Windows (Command Prompt)
netstat -ano | findstr :3641
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3641 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3641
From Windows
Test-NetConnection HOST -Port 3641
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3641

Block port 3641 in the firewall

ufw
sudo ufw deny 3641/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3641 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3641 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3641' -Direction Inbound -Protocol TCP -LocalPort 3641 -Action Block
ufw
sudo ufw deny 3641/udp
iptables
sudo iptables -A INPUT -p udp --dport 3641 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3641 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3641' -Direction Inbound -Protocol UDP -LocalPort 3641 -Action Block

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3639xap-ha3640netplay-port13642juxml-port3643audiojuggler

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