Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 673)

IPv6 Introduction
Software Reference for x310 Series Switches
C613-50046-01 REV A AlliedWare Plus TM Operating System - Version 5.4.4C 26.7
6. The Authentication header (AH). This verifies the integrity of the packet and its
headers.
7. The Encapsulating Security Payload (ESP) header. This encrypts a packet and verifies
the integrity of its contents.
8. The Upper Layer Protocol header. This indicates which protocol a higher layer (such as
the transport layer) is to process the packet with (for example, TCP).
The Internet Control Message Protocol (ICMPv6)
The Internet Control Message Protocol, ICMPv6, provides a mechanism for error reporting
and route discovery and diagnostics. It also conveys information about multicast group
membership, a function that is carried out by the Internet Group Management Protocol
(IGMP) in IPv4, and performs address resolution, which the Address Resolution Protocol
(ARP) performs in IPv4.
Significant aspects of ICMPv6 include neighbor discovery, which enables one device in a
network to find out about other nearby devices; and stateless address autoconfiguration,
which allows a device to dynamically determine its own IPv6 address.
ICMPv6 is also used to support the Ping v6 (Packet Internet Groper) and Trace route v6
functions that are used to verify the connections between networks and network devices.
Ping is used to test the connectivity between two network devices to determine whether
each network device can “see” the other device. Trace route is used to discover the route
used to pass packets between two systems running the IP protocol.
Both of these functions operate almost identically in IPv4 and IPv6. For more information,
see
“Ping” on page 24.10 .
Neighbor Discovery
Neighbor discovery is an ICMPv6 function that enables a router or a host to identify other
devices on its links. This information is then used in address autoconfiguration, to redirect
a node to use a more appropriate router if necessary, and to maintain reachability
information with its neighbors.
The IPv6 Neighbor Discovery protocol is similar to a combination of the IPv4 protocols
ARP, ICMP Router Discovery and ICMP Redirect.
The following table describes packet types involved with neighbor discovery.
To comply with Section 6.2.1 of RFC 2461, IPv6 Neighbor Discovery, the router does not
generate router advertisements by default.
Packet Type Description
router solicitation Packet in which a host sends out a request for routers to
generate advertisements.
router advertisement Allows routers to advertise their presence and other network
parameters. A router sends an advertisement packet in
response to a solicitation packet from a host.
neighbor solicitation Packet in which a node sends a packet to determine the link
layer address of a neighbor or to verify that a neighbor is still
active.
neighbor advertisement A response to a neighbor solicitation packet. These packets
are also used to notify neighbors of link layer address
changes.
redirect Informs hosts of a better first hop.