tailieunhanh - sams teach yourself tcp ip in 24 hours phần 2

quản lý một mạng TCP / IP • Làm thế nào để khắc phục sự cố các vấn đề mạng liên quan các chức danh . Sams Teach Yourself mạng trong 24 giờ ISBNgiới thiệu vững chắc để Sams công nghệ mạng Teach Yourself khắc phục sự cố mạng trong 24 giờ ISBNhướng dẫn của một người mới bắt đầu việc tìm kiếm và sửa chữa các vấn đề mạng | A Quick Look at TCP IP Networking 29 FIGURE A quick look at the basic TCP IP networking system. 2. The data segment passes to the Internet level where the IP protocol provides logical-addressing information and encloses the data into a datagram. 3. The IP datagram enters the Network Access layer where it passes to software components designed to interface with the physical network. The Network Access layer creates one or more data frames designed for entry onto the physical network. In the case of a LAN system such as ethernet the frame may contain physical address information obtained from lookup tables maintained From the Library of Athicom Parinayakosol 30 I HOUR 2 How TCP IP Works using the Internet layer ARP and RARP protocols. ARP Address Resolution Protocol translates IP addresses to physical addresses. RARP Reverse Address Resolution Protocol translates physical addresses to IP addresses. 4. The data frame is converted to a stream of bits that is transmitted over the network medium. Of course there are endless details describing how each protocol goes about fulfilling its assigned tasks. For instance how does TCP provide flow control how do ARP and RARP map physical addresses to IP addresses and how does IP know where to send a datagram addressed to a different subnet These questions are explored later in this book. Summary In this hour you learned about the layers of the TCP IP protocol stack and how those layers interrelate. You also learned how the classic TCP IP model relates to the seven-layer OSI networking model. At each layer in the protocol stack data is packaged into the form that is most useful to the corresponding layer on the receiving end. This hour discusses the process of encapsulating header information at each protocol layer and outlines the different terms used at each layer to describe the data package. Finally you got a quick look at how the TCP IP protocol system operates from the viewpoint of some of its most important protocols .