Ways to check if a website is really down
I got the inspiration for this post from the Download Squad article "Is this web site down for everyone or is it just you ?" which mentioned a service that would check if a website was down or if it was more likely to be a problem on the user's side. Some guys mentioned in the comments that the website checking service would display false results from time to time which in turn convinced me to write a post about other methods on how you can check if a website is up, or not.
Checking if a website is up or not should be speedy, you do not want to waste your time analyzing large log files if there is another faster way to accomplish the check. This article is therefor concentrating on methods that reveal results in a matter of seconds which are easy to interpretate.
If you know of a method that is missing let me know and I will check it out and add it if it makes a good fit. On we go with ways to check if a website is really down.
A ping basically sends an Hello to a server waiting for an response. If the response takes to long a timeout will occur. Ping is measured in ms, if it is incredibly high something is wrong with either your computer, the route in between or the destination.
The command is similar in Windows and Linux, just enter ping destination, with destination being an IP or domain name, and wait for the response.
One of the many online scripts that ping servers is located at Ping.eu. It offers other network tools like Traceroute and a port check as well.
You can compare Tracerouter with a list of all the roads that you travel until you reach your destination. Only that the roads are the servers in this case that your data is send through to reach their destination. If everything is fine the destination server should appear at the end, if it is not you could get timeouts for instance.
Traceroute Tool from the University of Princeton displays the traceroute between the University and another server on the Internet, you can enter the IP or domain name of the server.
Tracert is the command that you can use in Windows to trace the route between your computer and the destination. Use the command "tracert IP" or "tracert domain" to achieve this. Traceroute is the equivalent in Linux.
3. Domain Name System (DNS)
DNS errors most of the time occur when a website is freshly registered or moving to another server. It usually takes some time to update the DNS records to point at the new server. DNS is providing information much like your phone book is. Domain names are for us puny humans who have troubles remembering those server IP addresses (126.96.36.199 for Google for instance). Problems occur when the Nameservers who translate the human entered domain names into IP addresses have still the old IP in their records while the website is already up and running on the new IP.
You can use the online script DNS Report to receive a detailed report. Green results are fine, red ones point to failures and yellow ones are warnings.
Proxys can be used to establish connections to websites even if the direct route from your computer to theirs is somehow blocked. You can compare that to visiting a friend and using his computer to connect to a server that you cannot connect to. If it works it is somehow related to your computer or connection.
You can find hundreds of web based proxies at Proxy.org. Try some and see if you can connect to the website.
5. Ask someone
If you have direct contact to other users, be it in IRC, Skype, Instant Messengers or even forums, you can ask them if they would be kind enough to check a particular website for you. That`s practically a substitute to using a proxy.Advertisement