What is PING and how to use it to troubleshoot your Internet connectivity

What is PING and how to use it to troubleshoot your Internet connectivity

Ping is very simple, but highly effective computer networking tool, widely used by experts to perform basic network testing and troubleshooting.

It is available on every operating system, hence anyone can make use of it in case of any Internet connectivity issues to understand or narrow down the root cause.

Ping is available in command prompt of Windows, or terminal prompt on any other operating system like MacOS or Linux. In our example, we will use Windows command prompt, but reading and understanding the information from the output is the same on all operating systems.

Ping tool (command) will basically tell you whether a specific IP address is reachable or not.

In order to test your Internet connection, it is recommended to ping a reliable IP address, widely accessible across the Internet, thus basically testing if your Internet works or not. Such examples are Google’s DNS IP addresses “8.8.8.8” and “8.8.4.4” which are highly realiable and are commonly used even in professional enterprise networks to monitor Internet connectivity.

To use ping, you will need to go to a command prompt -> Start -> search “Command prompt” -> Open.  Then, enter the command “ping 8.8.8.8”:

The most important information you have gathered is the “Reply from 8.8.8.8”, meaning that you are able to reach Internet.

Next is the “Average packet roundtrip = 14ms”, which represents excellent response time, because Google’s servers are located everywhere around the globe and the nearest one will always respond,  thus minimizing the latency. Latency time highly depends on the distance between you and the reference server. Typical ping values in domestic networks should not exceed 50 ms.

However, at the distance between United States and Europe the ping value may be between 100 and 150 ms, which is considered normal.

When you are on the VPN, total round trip will be higher because the packet needs to travel to your home VPN server, from there to the destination server, plus the reverse path on the way back to your PC.

See my values on the KYHIP VPN using Economy light packet, being 2000 km away from home:

Notice the times are around 60ms now. These values represent very good Internet connection, which I also confirmed with a speed test that showed values of 30Mbps download and 15Mbps of upload.

It is amazing to realize that the actual round trip of these packets was 2000 km to Google and 2000 back to my pc, 4000km in total! In 60ms! Using pocket size devices!

Important thing to notice here is that all packets had similar response time, hence we can conclude there are no intermittent issues with my VPN speed and latency.

Next, packet loss is 0% which means my VPN connection is stable (you might want to test this with more packets using by adding “/t” at the end of your ping command). See below:

Stop the ping with Ctrl+C after a while. Here we have a sample of 19 packets, which is more relevant test than with 4 packets in the previous example. You can even leave the ping running for a few minutes, if you are suspecting on some intermittent issues.

At the end, rarely used in troubleshooting, but worth mentioning is the “TTL =116” information. TTL is abbreviation of Time-to-live and it is a mechanism used to avoid endless loops in computer networks. Each packet on the Internet can pass a maximum of 255 hops (Windows sets this value to 128 by default), thus your PC will send a packet of TTL=128 and with each hop TLL will decrement by 1. For our example, this means our packet passed 128-116 = 12 routers (hops) across the Internet to reach the Google server.

We have covered all the information provided in the ping output, in case you get a “Reply” from the server you have pinged. But how to read other ping outputs and what to do in those cases?  One of the common responses you might get is “PING: transmit failed. General failure.” This means that your PC is not connected to any router, neither via wireless nor a cable. Solution is to (re)connect to your wifi or cable connection.

“Request timed out.” Is the most common response when your VPN connection is not working. This means your PC is connected to your VPN client router, but the problem is with the VPN tunnel between the VPN client and the VPN server routers. Common issue is that VPN client router did not connect to the Internet via local connection properly. Login to the VPN client router and check the connection status. However, in rare cases, your home ISP connection might be down and your VPN server could be unreachable.