Next time you call your help desk, do you want to wow them with your networking knowledge? Using a command called “ping”, built right into your existing Mac, Windows, or Linux computer, will help identify basic connection problems. Okay, this might not be enough to “wow” your fellow team members, however they will appreciate that you started the debug process. And please remember that your Support personnel are debug specialists, so follow their instructions when they step you through the troubleshooting sequence.
You can use the
ping command built into your Mac OS X, Windows, or Linux computer to identify basic network connectivity issues. This can help you solve the problem and/or gain valuable debug information as a first step before calling support. Read below for details on how to launch a command line window and run
ping from your Mac OS X or Windows machine.
ping command is a simple way to verify that another computer can receive information from you. The original author, Mike Muuss, actually named the program after the “ping” sound that a submarine sends to detect objects in the water. If an echo of the ping comes back, it means that there is something out there. In fact,
ping uses the “Internet Control Message Protocol Echo Request” as part of its underlying software design.
In its simplest form, the
ping command provides two valuable pieces of information, whether the message was echoed back (
64 bytes from…) and how long it takes to receive the message back (e.g.,
time=6.396 ms). Depending on what type of computer you are using, you may even get a summary containing minimum, maximum, average, and more. The response time is shown in “ms”, or millisecond, which is 1/1000th of a second. A response time of 10ms or less is pretty fast, however values are often in the 100ms range. At much above 200ms you’ll probably notice that you have a sluggish connection.
When all is well:
This is what my
ping response looks like on my Mac OS X computer when everything is working normally here in Malaysia:
MacBook-Pro:~ ajm$ ping Google.com PING google.com (22.214.171.124): 56 data bytes 64 bytes from 126.96.36.199: icmp\_seq=0 ttl=55 time=6.396 ms 64 bytes from 188.8.131.52: icmp\_seq=1 ttl=55 time=6.368 ms 64 bytes from 184.108.40.206: icmp\_seq=2 ttl=55 time=26.773 ms 64 bytes from 220.127.116.11: icmp\_seq=3 ttl=55 time=6.984 ms ^C --- google.com ping statistics --- 4 packets transmitted, 4 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 6.368/11.630/26.773/8.746 ms
This is what my
ping response looks like on a Windows computer when everything is working well:
C:\Users\BJM>ping Google.com Pinging google.com [18.104.22.168] with 32 bytes of data: Reply from 22.214.171.124: bytes=32 time=6ms TTL=128 Reply from 126.96.36.199: bytes=32 time=15ms TTL=128 Reply from 188.8.131.52: bytes=32 time=6ms TTL=128 Reply from 184.108.40.206: bytes=32 time=6ms TTL=128 Ping statistics for 220.127.116.11: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 6ms, Maximum = 15ms, Average = 8ms
You can see from these examples that the connection is pretty good with average response times under 10ms.
When something is wrong (three examples):
So what would happen if I could not connect to
Google.com? For example #1, I simulate a broken network connection to my Mac by unplugging my router from the wall, and re-run the command. The first thing I notice is that it takes a lot longer for the command to respond:
MacBook-Pro:~ ajm$ ping google.com ping: cannot resolve google.com: Unknown host MacBook-Pro:~ ajm$
Or, for example #2, depending on exactly how the connection is failing:
PING google.com (18.104.22.168): 56 data bytes Request timeout for icmp\_seq 0 Request timeout for icmp\_seq 1 Request timeout for icmp\_seq 2 ^C
And sometimes, if I have a particularly flaky connection, I’ll see a mixture of these messages. For example #3, I can simulate this by connecting my Mac computer to a public Wi-Fi connection that is across the street:
PING google.com (22.214.171.124): 56 data bytes 64 bytes from 126.96.36.199: icmp\_seq=0 ttl=57 time=273.655 ms 64 bytes from 188.8.131.52: icmp\_seq=1 ttl=57 time=808.546 ms 64 bytes from 184.108.40.206: icmp\_seq=2 ttl=57 time=179.613 ms Request timeout for icmp\_seq 3 Request timeout for icmp\_seq 4 64 bytes from 220.127.116.11: icmp\_seq=5 ttl=57 time=374.612 ms Request timeout for icmp\_seq 6 ping: sendto: No route to host Request timeout for icmp\_seq 7 ping: sendto: No route to host Request timeout for icmp\_seq 8 ^C
In the first test,
ping told me that my machine could not even find the Internet address (IP
Google.com. In the second test, my computer remembered Google’s IP address, but could not actually reach the Google servers (
Request timeout). In the third test,
sendto: No route to host means that the network device knows where the Google servers are, but something along the digital pathway is broken.
Mac Users: How to run the
On a Mac, you typically run
ping from the terminal command line. To start the terminal, click the OS X Spotlight magnifying glass icon in the upper right of the desktop:
When the search window appears, type “terminal”, highlight “Terminal – Utilities”, and double-click (or hit
That will launch the terminal command window, and you can enter the command
ping Google.com shown in my examples:
Important Mac Tip : The
ping command will run forever if you don’t tell it to stop. To do that, press the
key (lower right on keyboard) and the
key. That will interrupt the test with a Control-C (
^C) and give back command line control. For Windows user, the command will stop by itself after a few iterations.
Windows Users: How to run the
Opening the Command Prompt differs between Windows versions 10, 8.1, 8, and 7; here’s a great guide at How To Open Command Prompt. On a Windows 7 machine, for example, click on the lower left Windows “Start” icon, and select “Command Prompt” and double-click (or hit
This will launch the command window, and you can enter the command
ping Google.com shown in the examples:
Now that you know how to use the
ping command, you can do basic troubleshooting of your network connection. With a little bit of creativity, you can work with your local IT support person or knowledge of your network topology and IP address (e.g.,
ping the router,
ping your ISP) to further identify network issues.