What does the “pipe” value mean in the output of “ping”?

When using the ping command, you may encounter a “pipe” value in the rtt statistics. To understand its meaning, I delved into the ping source code. The “pipe” number represents the maximum number of echo request packets that were simultaneously sent but not yet answered by an echo reply packet. However, they eventually receive a response. Normally, ping will send an echo request, wait for a second, and then send the next request. If it sends the second request before the first is answered, the pipe number increases by one. This pattern continues with subsequent requests. By pinging a system with a long round trip time and reducing the interval time, you can observe the pipe number increasing. For example, I first pinged a system in New Zealand using the regular method and then decreased the interval time significantly, resulting in a higher pipe value.


To top