Chapter 6. Network Layer

The Network Layer relies upon the services of the Data Link Layer to move messages along individual network segments, such as across an Ethernet collision domain or a WAN link. The Network Layer is responsible for end-to-end delivery of the message, where the Data Link Layer was only responsible for moving the message across one point-to-point link or across one collision domain or broadcast domain. (See Figure 6-1.)

Figure 6-1. The Network Layer in relation to the other OSI layers


Because the Network Layer and Data Link Layer are operating more or less independently of each other, each has its own addressing scheme and ...

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