The following topics are covered in this chapter:
- Describing the Packet Delivery Process
- Layer 1 Devices and Their Function
- Layer 2 Devices and Their Function
- Layer 2 Addressing
- Layer 3 Devices and Their Function
- Layer 3 Addressing
- Mapping Layer 2 Addressing to Layer 3 Addressing
- ARP Table
- Host-to-Host Packet Delivery
- Function of the Default Gateway
- Using Common Host Tools to Determine the Path Between Two Hosts Across a Network
In this chapter, I’m going to discuss the IP routing process. This is an important subject to understand since it pertains to all routers and configurations that use IP. IP routing is the process of moving packets from one network to another network using routers. And as before, by routers I mean Cisco routers, of course! However, we are going to use two different devices in this chapter—an IOS router and a Nexus switch with layer 3 capability. Both devices I’ll just refer to as a router because we are, well, routing in this chapter by using both devices in the same manner.
But before you read this chapter, you must understand the difference between a routing protocol and a routed protocol. A routing protocol is used by routers to dynamically find all the networks in the internetwork and to ensure that all routers have the same routing table. Basically, a routing protocol determines the path of a packet through an internetwork. Examples of routing protocols are RIP, RIPv2, EIGRP, and OSPF.
Once all routers know about ...