
Chapter 13 • IPv6 Neighbor Discovery 233
used for Neighbor Unreachability Detection as well as for address
resolution functions.
Options defined in RFC 2461 for the Router Advertisement message
include the source link layer address, the MTU value, and prefix
information (indicating which prefixes are local and which are not).
13.5 Summary
An ongoing challenge for IP networking has always been the need to
define mechanisms to allow nodes to interoperate across local link net-
works that are fundamentally different. The use of ARP and its various
different flavors on broadcast and nonbroadcast media has required the
creation of a whole family of services on