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Địa chỉ ngẫu nhiên trở thành địa chỉ mạng của nó (nếu một Macintosh không phải là đã sử dụng địa chỉ đó, nếu như vậy, mới chạy trên máy Mac sẽ tiếp tục tạo ra các địa chỉ ngẫu nhiên cho đến khi nó tìm thấy một trong đó là không sử dụng). | PART I Networking Overview CHAPTER 4 Internetworking Basics Repeaters Repeaters take the signal that they receive from network devices and regenerate the signal so that it maintains its integrity along a longer media run than is normally possible. Because all media types copper cable fiber optic cable and wireless media must deal with attenuation limiting the possible distance between network nodes repeaters are a great way to physically enlarge the network. Because repeaters are Physical layer devices they don t examine the data packets that they receive nor are they aware of any of the logical or physical addressing relating to those packets. This means that placing a repeater on a network doesn t slow down the flow of information on the network to any great degree. The repeater just sits on the network boosting the data signals received on one particular segment and passing it back out to another segment on the network as the data makes its way to its final destination see Figure . FIGURE Repeaters boost thedata signal from one network segment and pass it on to another network segment extending the size of the network. 70 PART I Internetworking Devices CHAPTER 4 Bridges Bridges are internetworking devices that operate at the Data Link layer of the OSI model. This means that they have greater capabilities networking-wise than Layer 1 devices like repeaters and hubs. Bridges are used to segment networks that have grown to a point where the amount of data traffic on the network media is slowing the overall transfer of information. Bridges which consist of the bridge hardware and some type of bridge operating system software have the capability to examine the MAC address also known as the hardware address remember it s burned onto the NIC in each computer on the network on each data packet that is circulating on the network segments that are connected to the bridge. By learning which MAC addresses are residents of the various segments on the overall network