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Port 20012 (ss-idi-disc)

IANA assigns port 20012 to ss-idi-disc: Samsung Interdevice Interaction discovery.

Registered (user) port, 1024-49151 UDP

Port 20012 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
ss-idi-disc UDP Samsung Interdevice Interaction discovery Hong Jungkih -

Check what is listening on port 20012

Linux: UDP 20012
sudo ss -ulnp 'sport = :20012'
Linux / macOS: which process owns the port
sudo lsof -nP -i :20012
Windows (Command Prompt)
netstat -ano | findstr :20012
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 20012

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 20012

Block port 20012 in the firewall

ufw
sudo ufw deny 20012/udp
iptables
sudo iptables -A INPUT -p udp --dport 20012 -j DROP
nftables
sudo nft add rule inet filter input udp dport 20012 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 20012' -Direction Inbound -Protocol UDP -LocalPort 20012 -Action Block

Related ports

20003commtact-https20005openwebnet20013ss-idi20014opendeploy

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