Ping - Internet Control Message Protocol

Ping - lets you send a special type of IMCP message called an **Echo Request

• IMCP Echo Request - essentially just asks a destination “hey, are you there?”
•  ​If the destination is up and ​running and able to communicate on the network, ​it’ll send back an ICMP echo reply message type. ​
• You can invoke the ping command from ​the command line of any modern operating system.
  • In its most basic use, ​you just type Ping and ​a destination IP or a fully qualified domain name
  • on Windows, ping defaults to sending 4 Echo Requests:

ICMP: Internet control message protocol is used by router or remote hosts to communicate error messages when network problems prevent delivery of IP packets

ICMP payload: Piece of the packet which lets the recipient of the message know which of their transmissions caused the error being reported