Port 43439 (eq3-update, eq3-config)

IANA assigns port 43439 to eq3-update, eq3-config: EQ3 firmware update.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

eq3-update TCP EQ3 firmware update eQ-3 Entwicklung GmbH -

eq3-config UDP EQ3 discovery and configuration eQ-3 Entwicklung GmbH -

Registry dates for this port: registered 2012-02-10, last modified 2014-05-09.

Linux: is anything listening on TCP 43439?

sudo ss -tlnp 'sport = :43439'

Linux: UDP 43439

sudo ss -ulnp 'sport = :43439'

Linux / macOS: which process owns the port

sudo lsof -nP -i :43439

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':43439 '

Windows (Command Prompt)

netstat -ano | findstr :43439

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 43439 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 43439

From Windows

Test-NetConnection HOST -Port 43439

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 43439

ufw

sudo ufw deny 43439/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 43439 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 43439 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 43439' -Direction Inbound -Protocol TCP -LocalPort 43439 -Action Block

ufw

sudo ufw deny 43439/udp

iptables

sudo iptables -A INPUT -p udp --dport 43439 -j DROP

nftables

sudo nft add rule inet filter input udp dport 43439 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block UDP 43439' -Direction Inbound -Protocol UDP -LocalPort 43439 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.