Internet Control Message Protocol( ICMP) version 6 (ICMPv6) is a protocol addition for the IPv6 protocol. Like the classic ICMP protocol, ICMPv6 is used for error mess aging and handling and is transmitted via datagrams over routing paths and networks.
During transmission, the ICMPv6 header can be corrupted. If a receiver detects that the transmitted data is incorrect, it reports this to the sending station. For this purpose ICMPv6 offers a wide variety of error and information messages, which are entered as digits in the Type field.
There are error messages, these are marked with the type numbers 0 to 127, and information messages, which occupy the number range from 128 to 255. Most type designations are described in the TCP/ IP standard documents( RFC) and can have an informal and experimental character.
In addition to the 8-bit Type field, the ICMPv6 header consists of the equally long Code field, the 16-bit Checksum field, and the ICMPv6 Message field. The two data fields, the Type field and the Code field, together specify the function of the ICMP message. The ICMPv6 protocol is also used in the Neighbour Discovery Protocol( NDP) and the Address Resolution Protocol( ARP).