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Port 3504 (ironstorm)

IANA assigns port 3504 to ironstorm: IronStorm game server.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ironstorm TCP IronStorm game server Arnaud Clermonte -
ironstorm UDP IronStorm game server Arnaud Clermonte -

Check what is listening on port 3504

Linux: is anything listening on TCP 3504?
sudo ss -tlnp 'sport = :3504'
Linux: UDP 3504
sudo ss -ulnp 'sport = :3504'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3504
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3504 '
Windows (Command Prompt)
netstat -ano | findstr :3504
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3504 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3504
From Windows
Test-NetConnection HOST -Port 3504
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3504

Block port 3504 in the firewall

ufw
sudo ufw deny 3504/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3504 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3504 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3504' -Direction Inbound -Protocol TCP -LocalPort 3504 -Action Block
ufw
sudo ufw deny 3504/udp
iptables
sudo iptables -A INPUT -p udp --dport 3504 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3504 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3504' -Direction Inbound -Protocol UDP -LocalPort 3504 -Action Block

Related ports

3502avinstalldisc3503lsp-ping3505ccmcomm3506apc-3506

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