When you are on the road and need to quickly test or troubleshoot connections to your server, you might not have immediate access to SSH. Four tools you can find from many online services can help you track down problems, make sure your site is running smoothly, or just gather important information.
1. Traceroute – From the Linux command line, traceroute allows you literally trace the route of a single connection from your computer to your server. With online traceroute tools, you can gather the same information. Furthermore, using a third-party server to run the traceroute is a good way to eliminate your own computer as the culprit.
2. Ping – With ping, you can get quick and easy feedback about how well your dedicated server is receiving connections and whether or not there is packet loss. Like traceroute, pinging from a third-party server is a great way to find out if others are experiencing the problems you are.
3. NSLookup – When you need nameserver information about your server, this is the tool to use. It is particularly useful if you have changed DNS or nameserver settings and need to find out if the changes have gone into effect.
4. Whois – Whois can give you detailed information about a domain or IP address, including nameservers and hosts. Outside of Linux and BSD, most desktop operating systems do not come with free whois software, making online tools easy and essential.
5. Port Scan – A port scan reveals whether or not a server is listening on a specified port and whether ports are open (and thus vunerable). Some online tools provide preset ports for common basic services to make it even easier for you to get started.