In this article we will look at the network configuration used at MKS Instruments. The areas covered will range from network infrastructure, to how it is implemented and how it is used. This document will also include the technology, hardware involved, and an example small-scale network diagram. There are many classes of IP addresses ranging from A up to E. Most large-scale businesses and offices use a Class A IP address scheme while smaller locations use Class C. The MKS office in San Jose uses a Class B IP scheme. Class B is used for medium-sized networks. A good example is a large university campus. IP addresses with first octets ranging from 128 to 191 are part of this class. Class B addresses also include the second octet as part of the network identifier. The other two octets are used to identify each host. This means that there are 16,384 (214) Class B networks each with 65,534 (216 -2) possible hosts for a total of 1,073,741,824 (230) unique IP addresses. The main office, which is a much larger office, uses a Class A IP addressing scheme. This class is for very large networks. IP addresses with the first octet from 1 to 126 are part of this class. The other three octets are used to identify each host. This means that there are 126 Class A networks each with 16,777,214 (224 -2) possible hosts for a total of 2,147,483,648 (231) unique IP addresses. The networks are divided into two groups. There is a Production network and a Development network. Each of these networks resides on its own separate subnet. The reason why networks are split in two is to prevent network overloads and slowdowns that would otherwise affect other MKS departments such as customer service or accounting. The production network involves non-development activities such as the customer service database, email, order entry, and accounting systems. The development network involves all areas related to product development. This network covers the server that stores the code base, the development system, development tools, software libraries, and software builds. Networks are controlled through the use of a router. This router is the only device that sees every message sent by any computer on either of the company's two networks. The router ensures that information does not go where it is not needed. This is critical to prevent large volumes of data from clogging the connections of other MKS departments.