Troubleshooting website connectivity issues is not a nice task, but sometimes it has to be done. A tool that I’ve come across that helps a great deal and pretty much gathers every tools required into one accessible place is ViewDNS.
ViewDNS is a web-based collection of troubleshooting tools listed on a single page, as well running your usual run-of-the-mill pings and traceroutes, the website gives you the ability to see if your website can be accessed behind Chinese or Iranian firewalls, perhaps not useful to everyone, but still a nifty little tool.
The site also gives the ability for users to see if a site of their choice is down through ‘Is My Site Down‘, essential for troubleshooting DNS or IP issues as regards to website accessibility. The tools runs ping requests, port scans and checks DNS resolution all in one go, screenshot at the bottom of this article.
You can run a Port Scanner, Ping and Traceroute tests to check for any connection specific issues, so a handy test using a traceroute through ViewDNS.info would be to compare that with a traceroute from the command line as well as your default gateway.
Beyond that you can check to see if your IP address is on any Spam Block lists or find the geographic location of an IP address.
Although all the features on the site are nothing new, it’s definitely worth a bookmark if you ever need to run any website diagnostics without having to go digging around for each tool manually.