Ipv6 Neighbor Discovery; Ipv6 Neighbor Solicitation Message - Cisco Nexus 7000 Series Configuration Manual

Nx-os unicast routing configuration
Hide thumbs Also See for Nexus 7000 Series:
Table of Contents

Advertisement

Chapter 3
Configuring IPv6
S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
A value of 58 in the Next Header field of the basic IPv6 packet header identifies an IPv6 ICMP packet.
The ICMP packet follows all the extension headers and is the last piece of information in the IPv6
packet.Within the IPv6 ICMP packets, the ICMPv6 Type and ICMPv6 Code fields identify IPv6 ICMP
packet specifics, such as the ICMP message type. The value in the Checksum field is computed by the
sender and checked by the receiver from the fields in the IPv6 ICMP packet and the IPv6 pseudo header.
The IPv6 header does not have a checksum. But a checksum is important on the transport layer to
Note
determine mis-delivery of packets. All checksum calculations that include the IP address in the
calculation must be modified for IPv6 to accommodate the new 128-bit address. A checksum is
generated using a pseudo header.
The ICMPv6 Data field contains error or diagnostic information that relates to IP packet processing.
Figure 3-11
Figure 3-11
Next header = 58
ICMPv6 packet
ICMPv6 Type

IPv6 Neighbor Discovery

You can use the IPv6 Neighbor Discovery Protocol (NDP) to determine whether a neighboring router is
reachable. IPv6 nodes use neighbor discovery to determine the addresses of nodes on the same network
(local link), to find neighboring routers that can forward their packets, to verify whether neighboring
routers are reachable or not, and to detect changes to link-layer addresses. NDP uses ICMP messages to
detect whether packets are sent to neighboring routers that are unreachable.

IPv6 Neighbor Solicitation Message

A node sends a Neighbor solicitation message, which has a value of 135 in the Type field of the ICMP
packet header, on the local link when it wants to determine the link-layer address of another node on the
same local link (see
neighbor solicitation message. The destination address is the solicited-node multicast address that
corresponds to the IPv6 address of the destination node. The neighbor solicitation message also includes
the link-layer address of the source node.
OL-20002-02
shows the IPv6 ICMP packet header format.
IPv6 ICMP Packet Header Format
ICMPv6 Code
ICMPv6 Data
Figure
3-12). The source address is the IPv6 address of the node that sends the
Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
IPv6 basic header
ICMPv6 packet
Checksum
Information About IPv6
3-13

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents