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Port 18516 (heythings)

IANA assigns port 18516 to heythings: HeyThings Device communicate service.

Registered (user) port, 1024-49151 UDP

Port 18516 is normally used over UDP; the checker tests TCP only, so a "filtered" result does not mean the UDP service is down.

IANA assignment

Service nameProtoDescriptionAssigneeReference
heythings UDP HeyThings Device communicate service
Defined TXT keys: heythings Guangdong OPPO Mobile Telecommunications Corp Ltd -

Registry dates for this port: registered 2020-05-13.

Check what is listening on port 18516

Linux: UDP 18516
sudo ss -ulnp 'sport = :18516'
Linux / macOS: which process owns the port
sudo lsof -nP -i :18516
Windows (Command Prompt)
netstat -ano | findstr :18516
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 18516

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 18516

Block port 18516 in the firewall

ufw
sudo ufw deny 18516/udp
iptables
sudo iptables -A INPUT -p udp --dport 18516 -j DROP
nftables
sudo nft add rule inet filter input udp dport 18516 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 18516' -Direction Inbound -Protocol UDP -LocalPort 18516 -Action Block

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