our own ISP/Internet Service Provider implements geo-restriction or others This tool doesn't use virtual network to reach the host, just common straight forward http (TCP)
the browser "detected" the site as malicious, it then would prevent any connection to it (via that browser)
or, our network proxy/DNS sumthin (ISP or firewall related)
or, the actual site is:
doing a periodical maintenance
or, maybe having super large connections (actual traffic or DDoS)
or, the whole site just offline (on purpose or not)
or, a part of that site (path) is deleted from the server
or, others....
Therefore, this was built to check whether a particular site is actually down or just from our side.
Anywhale, this tool is implementing:
Python's module, httplib (plus other supporting modules to render this page and data transfer plus others), to get only the headers response of a particular site from our back-end. This can be substituted/enhanced/equipped with other Python's module(s) or your own module. Depends on what you need. This can also be done using other programming languages: PHP, Ruby, Node, Java, .Net, etc. This one is using Python power! Activate!
The XHR (XMLHttpRequest) control (JavaScript/ECMAScript) to our back-end to trigger the validity checking.
The custom input control (JavaScript/ECMAScript) on the front-end, to kind of check whether the input is sort of a URL.
Pure CSS framework, to make it neat to look at. Or sumthin similor.