From a terminal
# your public IP curl https://a.rvrwlk.net/ip # is a port open? (from AWS us-east-1) curl https://a.rvrwlk.net/tcpping/example.com/443 # the network path to a host curl https://a.rvrwlk.net/traceroute/example.com # DNS: name / type / @resolver curl https://a.rvrwlk.net/dig/example.com/MX/@1.1.1.1 # add ?format=json to any of them for JSON curl 'https://a.rvrwlk.net/ip?format=json'