The sys admin's daily grind – paping

A Better ping

Article from Issue 180/2015
Author(s):

Like every sys admin, Charly occasionally throws a pebble at a machine to see if it is still alive. If the other end does not respond to the ping, that does not always mean it's dead. Maybe the pebble just missed.

Hi there! Anybody home? Quite often, admins need to make sure that at least the physical connection between two computers is still up – or back up. Obviously, ping is the tool of choice when it comes to proving or refuting accessibility. However, there are cases in which a firewall blocks the ICMP ping. Anyone with a modicum of knowledge can save the energy they would otherwise waste cussing and instead type:

nmap -p <port>

Don't cheer too soon, though, because often an intrusion prevention system blocks the Nmap signature of the workaround.

[...]

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