Neat tools to check for open ports that go through your firewall. http://portquiz.net/ >This server listens on all TCP ports, allowing you to test any outbound TCP port. You have reached this page on port 80 (from http host header). Your network allows you to use this port. (Assuming that your network is not doing advanced traffic filtering.) Network service: http Your outgoing IP: 207.46.170.123 https://about.ipv4.cat/ >What is ipv4.cat? ipv4.cat is a server that simply replies with your IP address on all TCP ports. How is this useful? This provides a way of determining your public IP address from command line with the least amount of typing possible, without requiring the installation of any software. Similar to portquiz.net, it also provides a way of checking for outbound firewall blocks. ipv4.cat differs from services like ifconfig.me in that it returns a raw TCP response and therefore doesn't require a HTTP client. Example uses ftp is recommended, as it is short, the most universal method across operating systems and is included in Windows by default (unlike telnet). ftp ipv4.cat telnet ipv4.cat ncat ipv4.cat curl ipv4.cat http://ipv4.cat (limited browser support) On a windows box you could install psping from Sysinternals' pstools to TCP ping: psping <example.com>:port