QandAs: Tech

What is a ping?

Answer:
A ping is a tool used by computers to initiate

an Internet Control Message Protocol Echo Request. This request helps the computer know if the receiving machine is online and available.

ICMP Echo Requests, also known as Pings, are used both legitimately and maliciously. In their legitimate use, they are similar to knocks on a door - a simple way of checking whether another computer is online and available. In their malicious use, they are used for finding targets for attack by hackers.

ICMP Echo Requests wait for an ICMP Echo Reply, which tells one computer that the other is available for communication. ICMP Echo Replies also tell malicious users that the target is there and able to be attacked. Most network routers and Internet Service Providers have the ability to disable the ICMP Echo Replies, but that option has to be manually specified by the user.

Even shutting down ICMP Echo Replies does not guarantee security. An ICMP Echo Reply of "Destination Host Unreachable" tells the malicious attacker that the target was found on the network but is currently offline, which usually means they will try again later. The most secure ICMP Echo Reply is "Request Timed Out" or "Time-To-Live Exceeded", which tells a malicious attacker there is no known machine or user at the targeted address.