嵌入式linux中文站在线图书

Previous Page
Next Page

Chapter 26. Neighboring Subsystem: Concepts

This chapter describes why and when a neighboring protocol is used and lays out its major tasks. It is deliberately a general overview that makes only passing references to particular neighboring protocols such as ARP. It covers such general issues as:

  • The tasks taken on by a general neighboring infrastructure

  • Why caching is valuable

  • The states a neighbor entry in the cache can take

  • Reachability detection and Network Unreachability Detection (NUD)

  • What proxying is for

The terminology used in the Linux kernel source code follows the IPv6 neighbor discovery model described in RFC 2461 in the section "Neighboring Protocols," but we will try to keep the discussion as protocol-independent as possible.

The terms L2 address, Layer two address, hardware address, MAC address, and link layer address are commonly used to refer to the same concept. In this chapter, we will mostly use the first term.


Previous Page
Next Page