Internet Control Message Protocol for IPv6 (ICMPv6)
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4/8/2010
Internet Control Message Protocol for IPv6 (ICMPv6) enables hosts and routers that use IPv6 communication to report errors and send simple echo messages. ICMPv6 is a required IPv6 standard defined in RFC 2463.
The following table shows the framework technology that the ICMPv6 protocol also provides.
| Technology | Description |
|---|---|
Multicast Listener Discovery (MLD) |
Multicast Listener Discovery (MLD) enables you to manage subnet multicast membership for IPv6. MLD is a series of three ICMPv6 messages that replace the Internet Group Management Protocol (IGMP) that is used for IPv4. For more information, see Multicast Listener Discovery (MLD). |
Neighbor Discovery (ND) |
Neighbor Discovery is a series of five ICMPv6 messages that manage node-to-node communication on a link. Neighbor Discovery replaces Address Resolution Protocol (ARP), ICMPv4 Router Discovery, and the ICMPv4 Redirect message and provides additional functions. For more information, see Neighbor Discovery (ND). |
Typically, ICMPv6 messages are sent when an IPv6 packet cannot reach its destination.
ICMPv6 messages are encapsulated and sent as the payload of IPv6 packets. Because they are carried in IPv6 packets, they are unreliable. The following illustration shows the relationship of the ICMPv6 message and the IPv6 packet.
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The ICMPv6 header identifies the different types of ICMPv6 messages.
The following table shows ICMPv6 messages that are not related to Multicast Listener Discovery (MLD) or Neighbor Discovery (ND).
| ICMPv6 message | Description |
|---|---|
Destination Unreachable |
An error message that informs the sending host that a packet cannot be delivered. |
Packet Too Big |
An error message that informs the sending host that the packet is too large to forward. |
Time Exceeded |
An error message that informs the sending host that the Hop Limit of an IPv6 packet has expired. |
Parameter Problem |
An error message that informs the sending host that an error was encountered in processing the IPv6 header or an IPv6 extension header. |
Echo Request |
An informational message that is used to determine whether an IPv6 node is available on the network. |
Echo Reply |
An informational message that is used to reply to the ICMPv6 Echo Request message. |
You can use either the Icmp6SendEcho2 API or the ping command to send ICMPv6 Echo Request messages and record the receipt of ICMPv6 Echo Reply messages. With ping, you can detect network or host communication failures and troubleshoot common IPv6 connectivity problems.
See Also
Reference
Concepts
Core Protocols of IPv6
Internet Group Management Protocol (IGMP)