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Port 8204 (lm-perfworks)

IANA assigns port 8204 to lm-perfworks: LM Perfworks.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
lm-perfworks TCP LM Perfworks Chris Flynn -
lm-perfworks UDP LM Perfworks Chris Flynn -

Check what is listening on port 8204

Linux: is anything listening on TCP 8204?
sudo ss -tlnp 'sport = :8204'
Linux: UDP 8204
sudo ss -ulnp 'sport = :8204'
Linux / macOS: which process owns the port
sudo lsof -nP -i :8204
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':8204 '
Windows (Command Prompt)
netstat -ano | findstr :8204
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 8204 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 8204
From Windows
Test-NetConnection HOST -Port 8204
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 8204

Block port 8204 in the firewall

ufw
sudo ufw deny 8204/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 8204 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 8204 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 8204' -Direction Inbound -Protocol TCP -LocalPort 8204 -Action Block
ufw
sudo ufw deny 8204/udp
iptables
sudo iptables -A INPUT -p udp --dport 8204 -j DROP
nftables
sudo nft add rule inet filter input udp dport 8204 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 8204' -Direction Inbound -Protocol UDP -LocalPort 8204 -Action Block

Related ports

8201trivnet28202aesop8205lm-instmgr8206lm-dta

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