17NAS Precise NAT Detection Tool
Go beyond browser WebRTC limits and identify NAT1/NAT2/NAT3/NAT4 accurately
1 Open a terminal and run the command
macOS
Windows
Linux
ARCH=$(uname -m); [ "$ARCH" = arm64 ] && FILE=17nas-nat-test-darwin-arm64 || FILE=17nas-nat-test-darwin-amd64; curl -fsSL -o 17nas-nat-test "https://17nas.com/downloads/$FILE" && chmod +x 17nas-nat-test && ./17nas-nat-test --lang en
How do I open Terminal? Press
Command + Space, type “Terminal” and press Enter. Paste the command above and press Enter again. 2 Authorize in the browser
The authorization page opens automatically. Sign in or register if needed; once authorized, the terminal starts the test automatically.
3 Review the precise result
The terminal shows the NAT classification and creates an online report link.
# Example output
NAT type: Port Restricted Cone NAT
NAT level: NAT3
Connectivity: Moderate
Report code: ABCD-1234
Full report: https://17nas.com/nat-report/ABCD-1234
Why is it more precise than the browser test?
Precise classificationNative UDP sockets distinguish Full Cone, Restricted and Symmetric NAT
Fast detectionNo installer; one command usually returns a result in seconds
Privacy-awareLocal UDP test with masked IP addresses in public reports
Online reportCreate a shareable report with improvement suggestions
AutomationAfter first authorization, use --json in scripts, monitoring and CI