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Port 11171 (snss)

IANA assigns port 11171 to snss: Surgical Notes Security Service Discovery (SNSS).

Registered (user) port, 1024-49151 UDP

Port 11171 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
snss UDP Surgical Notes Security Service Discovery (SNSS) David Lethe -

Registry dates for this port: registered 2010-12-24.

Check what is listening on port 11171

Linux: UDP 11171
sudo ss -ulnp 'sport = :11171'
Linux / macOS: which process owns the port
sudo lsof -nP -i :11171
Windows (Command Prompt)
netstat -ano | findstr :11171
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 11171

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 11171

Block port 11171 in the firewall

ufw
sudo ufw deny 11171/udp
iptables
sudo iptables -A INPUT -p udp --dport 11171 -j DROP
nftables
sudo nft add rule inet filter input udp dport 11171 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 11171' -Direction Inbound -Protocol UDP -LocalPort 11171 -Action Block

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11164suncacao-csa11165suncacao-websvc11172oemcacao-jmxmp11173t5-straton

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