Basic Network Design Cisco（基本的网络设计思科）.pdfVIP

C H A P T E R 3 Basic Network Design Overview The main function of the manufacturing zone is to isolate critical services and applications that are important for the proper functioning of the production floor control systems from the enterprise network (or zone). This separation is usually achieved by a demilitarized zone (DMZ). The focus of this chapter is only on the manufacturing zone. This chapter provides some guidelines and best practices for IP addressing, and the selection of routing protocols based on the manufacturing zone topology and server farm access layer design. When designing the manufacturing zone network, Cisco recommends that future growth within the manufacturing zone should be taken into consideration for IP address allocation, dynamic routing, and building server farms. Assumptions This chapter has the following starting assumptions: • Systems engineers and network engineers have IP addressing, subnetting, and basic routing knowledge. • Systems engineers and network engineers have a basic understanding of how Cisco routers and switches work. IP Addressing An IP address is 32 bits in length and is divided into two parts. The first part covers the network portion of the address and the second part covers the host portion of the address. The host portion can be further partitioned (optionally) into a subnet and host address. A subnet address allows a network address to be divided into smaller networks. Stat