To Wit:

*Excellent, heart-warming tale of exploration and discovery. Using deft allegory, the authors have provided an insightful and intuitive explanation of one of Unix’s most venerable networking utilities. Even more stunning is that they were clearly working with a very early beta of the program, as their book first appeared in 1933, years (decades!) before the operating system and network infrastructure were finalized.*

https://diffendoofers.wordpress.com/2014/04/17/the-story-abo...

  Ping goes back a long way. It was originally written by Mike Muuss while at the U. S. Army Ballistic Research Laboratory, in 1983, before I was born.