The fact of the matter is that ‘ping’, while a good (but not 100% even here) tool to determine if traffic can go from one IP to another, is a lousy tool for determining if anything more than layer three is working. The fact of the matter is that the network layer, which is where IP lives, is not one you care about in 99.999% of cases. Do you care that you can ping Google, even though your browser spins indefinitely trying to open or gets a Connection Refused when trying to pull up the page (not that this happens with Google much…. maybe hotmail would be a better example)? No, of course not… all you really care about is that a service is not working, which is more obvious at layer four (not three), and ping doesn’t care a thing about it.

Another silly example: Can you ping your workstation? How about your coworker’s workstation? Sure, but does that mean they are running a web server that you can access? Of course not, though they may be. Testing for a service is much more important and relevant for most of us, but we’re too stuck on ping. In the IT world (vs. the end user world) this is even more critical because we test services that we setup on odd ports in locked-down environments that may, annoyingly, block ICMP packets (including pings).