<Li> Checksum (16 bits), calculated with the ICMP part of the packet (the IP header is not used). It is the 16 - bit one's complement of the one's complement sum of the ICMP message starting with the Type field </Li> <Li> Header Data (32 bits) field, which in this case (ICMP echo request and replies), will be composed of identifier (16 bits) and sequence number (16 bits). </Li> <Li> ICMP Payload: payload for the different kind of answers; can be an arbitrary length, left to implementation detail . However, the packet including IP and ICMP headers must be less than the maximum transmission unit of the network or risk being fragmented . </Li> <P> The echo request ("ping") is an ICMP / ICMP6 message . </P>

Use the internet to determine more details about the protocol that the ping program uses