The Illustrated Network- P26:In this chapter, you will learn about the protocol stack used on the global public Internet and how these protocols have been evolving in today’s world. We’ll review some key basic defi nitions and see the network used to illustrate all of the examples in this book, as well as the packet content, the role that hosts and routers play on the network, and how graphic user and command line interfaces (GUI and CLI, respectively) both are used to interact with devices. | CHAPTER 8 Routing 219 bsdserver Inxclient winsvr2 wincli2 eth0 MAC 00 0e 0C 3b 87 32 Intel_3b 87 32 IPv6 fe80 20e Cff fe3b 8732 eth0 MAC 00 b0 d0 45 34 64 Dell_45 34 64 IPv6 fe80 2b0 d0ff fe45 3464 LAN2 MAC 00 0e 0c 3b 88 56 Intel_3b 88 56 IPv6 fe80 20e cff fe3b 8856 LAN2 MAC 00 02 b3 27 fa 8c IPv6 fe80 202 b3ff fe27 fa8c Ethernet LAN Switch with Twisted-Pair Wiring 220 PART II Core Protocols Routing Table and Forwarding Table There are really two different types of network tables used in routers and hosts and we ll distinguish them in this chapter. The routing table holds all of the information that a device knows about network addresses and interfaces and is usually held in a fairly user-friendly format such as a standard set of tables or even a database often with metrics costs associated with each route. A forwarding table on the other hand is usually a machine-coded internal one that contains the routes actually used by the device to reach destinations. In most cases the routing one holds more information than is distilled in the forwarding table. ROUTERS AND ROUTING TABLES The router that attaches LAN1 to the world is CEO a Juniper Networks router. Let s look at the information in the routing table on CEO. admin@CE0 show route 5 destinations 5 routes 5 active 0 holddown 0 hidden Active Route - Last Active Both 0 Static 5 3d 02 59 20 via ge-0 0 24 Direct 0 2d 14 25 52 via ge-0 0 32 Local 0 2d 14 25 52 Local via ge-0 0 24 Direct 0 2d 14 25 52 via fe-1 3 32 Local 0 2d 14 25 52 Local via fe-1 3 5 destinations 6 routes 6 active 0 holddown 0 hidden Active Route - Last Active Both 0 Static 5 2d 13 50 23 via ge-0 0 fe80 64 Direct 0 2d 14 25 53 via fe-1 3 fe80 205 85ff fe88 ccdb 128 Local 0 2d 14 25 53 Local via fe-1 3 fc00 fe67 32 Static 5 2d 13 50 23 via ge-0 0 fc00 ffb3 d4 b 64 Direct 0 2d 10 45 08 via fe-1 3 .
