User talk:Rolyms

ICMP IPv6 == ==

The ICMP implementation is specific of IP version 4 (IPv4). IP version 6 needed a new version ICMP. The descriptions are not complete still but already some characteristics are known like:

•	ICMP for IPv6 will use a new number of protocols to distinguish it of ICMPv4.

•	The format of head ICMP will remain equal.

•	The lengths of the fields of the messages will change to adjust to the IPv6 messages, that will be of greater length.

•	The values “Type” and “Code” will change. Some values little used will be eliminated.

•	The size of messages ICMP will increase with the purpose of operating the maximum size increased of the packages that IPv6 can transmitter without fragmenting.

•	The variant “Fragmentation Required” of message ICMP “unreachable Destination” will be replaced by the message “Packet Too Big” that will include the MTU (“Maximum Transmission Unit”) of exit in which the problem has been located.

•	IGMP will be fused with ICMP.

Internet Control Message Protocol (ICMP),is a required protocol tightly integrated with IP. ICMP messages, delivered in IP packets, are used for out-of-band messages related to network operation or mis-operation.

Of course, since ICMP uses IP, ICMP packet delivery is unreliable, so hosts can't count on receiving ICMP packets for any network problem.

The ICMPv6 (Internet Control Message Protocol version 6) is an integral part of the IPv6 architecture and must be completely supported by all IPv6 implementations.

ICMPv6 combines functions previously subdivided among different protocols, such as ICMP (Internet Control Message Protocol version 4), IGMP (Internet Group Membership Protocol), and ARP (Address Resolution Protocol), and it introduces some simplifications by eliminating obsolete types of messages no longer in use.

ICMPv6  The Protocol of Messages of Control of Internet (Internet Control Message Protocol), described originally in document RFC792 for IPv4, has been updated to allow its use under IPv6. The resulting protocol of this modification is ICMPv6, and a value has been assigned to him, for the field of “following head”, equal to 58. ICMPv6 is integral part of IPv6 and must totally be incorporated to any implementation of node of the new IP.

ICMPv6 is used by IPv6 to report errors that are during the processing of the packages, as well as for the accomplishment of other functions relative to the layer “Internet”, like diagnoses (“ping”). The generic format of the ICMPv6 messages is the following one:

The field “type” indicates the type of message, and its value determines the format of the rest of the head. The field “code” depends on the type of message, and it is used to create an additional level of hierarchy for the classification of the message. The checksum or code of redundancy allows to detect errors us in the ICMPv6 message.

The ICMPv6 messages are grouped in two types or classes: informative message of error and messages. The error messages have zero in the bit of greater weight of the field “type”, reason why their values are located between 0 and 127. The values of the informative messages oscillate between 128 and 255. The messages defined by the basic specification are the following ones:

This working in new types of messages, being the most interesting of them defined one in an IETF rough draft (draft-IETF-ipngwg-ICMP-name-lookups-05.txt), that will allow to ask for to a node complete information like its “name of completely qualified dominion” (Fully-Qualified-Domain-Name). For security reasons, the ICMPv6 heads can be authenticated and encrypted, using the corresponding head. The use of this mechanism allows, in addition, the prevention of attacks ICMP, like the well-known “Negation on watch” (Two or Denial of Service Attack).

Collaboration students class Protocols *3* (IDE 0310444, IDE 0310111) University Galileo, Guatemala.