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Port 33334 (speedtrace, speedtrace-disc)

IANA assigns port 33334 to speedtrace, speedtrace-disc: SpeedTrace TraceAgent.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
speedtrace TCP SpeedTrace TraceAgent Holger Heinrich -
speedtrace-disc UDP SpeedTrace TraceAgent Discovery Holger Heinrich -

Registry dates for this port: registered 2012-02-01.

Check what is listening on port 33334

Linux: is anything listening on TCP 33334?
sudo ss -tlnp 'sport = :33334'
Linux: UDP 33334
sudo ss -ulnp 'sport = :33334'
Linux / macOS: which process owns the port
sudo lsof -nP -i :33334
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':33334 '
Windows (Command Prompt)
netstat -ano | findstr :33334
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 33334 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 33334
From Windows
Test-NetConnection HOST -Port 33334
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 33334

Block port 33334 in the firewall

ufw
sudo ufw deny 33334/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 33334 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 33334 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 33334' -Direction Inbound -Protocol TCP -LocalPort 33334 -Action Block
ufw
sudo ufw deny 33334/udp
iptables
sudo iptables -A INPUT -p udp --dport 33334 -j DROP
nftables
sudo nft add rule inet filter input udp dport 33334 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 33334' -Direction Inbound -Protocol UDP -LocalPort 33334 -Action Block

Related ports

33331diamondport33333dgi-serv33434traceroute33435mtrace

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