Chapter 7. Networks

A site’s network is the foundation of its infrastructure. A poorly built network affects everyone’s perception of all other components of the system. A network cannot be considered in isolation. Decisions made as part of the network design and implementation process influence how infrastructure services are implemented. Therefore, the people who are responsible for designing those services should be consulted as part of the network design process.

We cannot explain every detail of network design and implementation in this short chapter. Entire shelves of books are devoted to the topic. However, we can relate the points we have found to be the most important. An excellent starting point is Perlman (1999). For Transmission Control Protocol/Internet Protocol (TCP/IP), we recommend Stevens (1994) and Comer (2000). To understand how routers and switches work, see Berkowitz (1999). Berkowitz (1998) also has written a book on network addressing architectures. For more information on specific technologies, see Black (1999). For WANs, see Marcus (1999) and Feit (1999). For routing protocols, see Black (2000). Other books concentrate on a single protocol or technology, such as Open Shortest Path First (OSPF) [Moy 2000, Thomas 1998a]; Enhanced Interior Gateway Routing Protocol (EIGRP) [Pepelnjak 2000]; Border Gateway Protocol (BGP) [Stewart 1999, Halabi and McPherson 2000]; Mail Protocol Label Switching (MPLS), VPNs, and QoS [Black 2001, Guichard and Pepelnjak 2000, Lee 1999, Vegesna 2001, Keagy 2000, and Maggiora et al. 2000]; multicast [Williamson 2000]; Asynchronous Transfer Mode (ATM) [Pildush 2000]; and Ethernet [Spurgeon 2000].