Introduction To Ipv6 Neighbor Discovery Protocol - H3C S3100 Series Operation Manual

hexadecimal number FFFE needs to be inserted in the middle of MAC addresses (behind the 24
high-order bits).To ensure the interface identifier obtained from a MAC address is unique, it is
necessary to set the universal/local (U/L) bit (the seventh high-order bit) to "1". Thus, an interface
identifier in EUI-64 format is obtained.
Figure 1-2 Convert a MAC address into an EUI-64 address

Introduction to IPv6 Neighbor Discovery Protocol

The IPv6 neighbor discovery protocol (NDP) uses five types of ICMPv6 messages to implement the
following functions:
Address resolution
Neighbor unreachability detection
Duplicate address detection
Router/prefix discovery
Address autoconfiguration
Redirection
Table 1-3 lists the types and functions of ICMPv6 messages used by the NDP.
Table 1-3 Types and functions of ICMPv6 messages
ICMPv6 message
Neighbor solicitation (NS) message
Neighbor advertisement (NA) message
Router solicitation (RS) message
Router advertisement (RA) message
Redirect message
Used to acquire the link-layer address of a neighbor
Used to verify whether the neighbor is reachable
Used to perform a duplicate address detection
Used to respond to a neighbor solicitation message
When the link layer address changes, the local node initiates a
neighbor advertisement message to notify neighbor nodes of the
change.
After started, a host sends a router solicitation message to request
the router for an address prefix and other configuration information
for the purpose of autoconfiguration.
Used to respond to a router solicitation message
With the RA message suppression disabled, the router regularly
sends a router advertisement message containing information such
as address prefix and flag bits.
When a certain condition is satisfied, the default gateway sends a
redirect message to the source host so that the host can reselect a
correct next hop router to forward packets.
1-5
Function