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Port 3804 (iqnet-port)

IANA assigns port 3804 to iqnet-port: Harman IQNet Port.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
iqnet-port TCP Harman IQNet Port Bruce Vander Werf -
iqnet-port UDP Harman IQNet Port Bruce Vander Werf -

Registry dates for this port: registered 2004-02.

Check what is listening on port 3804

Linux: is anything listening on TCP 3804?
sudo ss -tlnp 'sport = :3804'
Linux: UDP 3804
sudo ss -ulnp 'sport = :3804'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3804
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3804 '
Windows (Command Prompt)
netstat -ano | findstr :3804
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3804 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3804
From Windows
Test-NetConnection HOST -Port 3804
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3804

Block port 3804 in the firewall

ufw
sudo ufw deny 3804/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3804 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3804 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3804' -Direction Inbound -Protocol TCP -LocalPort 3804 -Action Block
ufw
sudo ufw deny 3804/udp
iptables
sudo iptables -A INPUT -p udp --dport 3804 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3804 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3804' -Direction Inbound -Protocol UDP -LocalPort 3804 -Action Block

Related ports

3802vhd3803soniqsync3805tcpdataserver3806wsmlb

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