If you want to make sure that network resources or domains on the Internet are accessible, you have plenty of options to do so.
While you can run tests manually, it is not practicable as you would have to repeat the test regularly to make sure it does not go down.
Network monitoring software and online monitoring services like Deez.io can be used to automate the process.
Ping Viewer is a free portable program for Windows that has been designed for that and more. The program is a network monitor that you can use to monitor devices on a local area network but also domains and machines on the Internet.
You can run a wizard on start if you want which scans network IP addresses and adds any device and server it finds automatically, or add IP addresses and domain names manually instead.
While designed with local networks in mind, webmasters can use the program to test connections to servers and domain names regularly to make sure they are up and running.
To add a new site, right-click and select add target from the context menu.
The action opens an extensive configuration page. The only mandatory field on it is the IP address, domain name or machine name, everything else is optional.
The program supports several different target types with the default one being ICMP Ping. You can switch that to other options such as TCP connect or PingView server. The latter option allows you to collect information collected by the server on the local system.
Additional options include adding a TCP port for the connection, an IP address or MAC address, or to select a previously configured proxy server for the connection.
Once you have added at least one device you can start the monitoring via the actions menu. If you have selected to ping domain names for instance, those domain names will be ping every 30 seconds by default.
Ping Viewer displays information about the connection attempt in the log and highlights successful (green) and unsuccessful (red) connection attempts directly in the interface.
The program preferences allow you to modify various test parameters. You can modify the connection interval, define different timeout values, or configure messages and sound notifications.
The application keeps track of connection attempts and lists statistics about them in its interface. When you select an address or device, its statistics are displayed in the middle row of the interface.
There you find listed the total number of attempts and failures, the IP address, last contact and other information.
One of the interesting features of Ping Viewer is that you can run the program on remote servers. This can be useful if the computer you are working on is not on or online 24/7 while the server is. You could then pull data from the server regularly to get 24/7 connection stats and information.
A good starting point for the configuration of this option is the help file on the developer's website.