The Open Port Check Tool at will only test your public IP address (your router).

The passing grade also means that the router does not reply to Ping commands on the WAN port. If all is well, it will say 'Passed' in green and the status of every port will be 'stealth'. Then, move on to the 'All Service Ports' which tests all the ports from zero to 1055 and takes about 70 seconds to run.

Steve Gibson's Shields UP! is an oldie but goodie.

Best response is 'no publicly accessible services' Further tests of your public IP address are available on the Shodan page.

See what Censys.io knows about your public IP address here: censys.io/ipv4/109.200.233.75.See what Shodan knows about this IP address here: shodan.io/host/109.200.233.75.'filtered' to Nmap) means data sent to the port generates no response at all. 'refused' in Nmap lingo) is accessible, but there is no application listening on it. Port Status: An 'open' port responds to unsolicited incoming requests. This dumbs it down to function only as a modem. For your router to be your public face on the Internet, the gateway needs to be put in Bridge mode. However, if it is a gateway device (combination modem, router and perhaps even a telephone adapter) from your ISP, then the device visible to the outside world may be the gateway rather than your router. The third case involves the box your router is directly connected to. Likewise, with Tor you end up testing the Tor exit node rather than your router. If you are connected to a VPN, the public sees the VPN server, rather than your router. There are, however, three instances where the firewall tests are not communicating with your router. All devices connected to the same router have the same public IP address. Usually, this IP address belongs to the router your computing device (tablet, phone, computer) is connected to. The firewall tests below communicate with what they see as your public IP address. The computer where this website resides goes by the name and the IP address 216.92.136.14. Level setting: Every computing device on the Internet is assigned a number. It is never obvious, yet it is critically important, to know whose DNS servers you are using. It explains DNS and lists multiple websites that report on the currently in effect DNS server(s). The topic of Testing Your DNS Servers has been moved to a new page.

Router configuration page netgear