Packet Guide to Routing and Switching

Chapter 1. Routing and Switching Strategies

The previous book in this series, The Packet Guide to Core Network Protocols, covered the IPv4 protocols, masking, and devices that are part of every network. Now it’s time to take on the routing and switching for the network. There are an astonishing number of table-based decisions that have to be made in order to get a single packet across a network, let alone across a series of networks. Not limited to routers, switches, and access points, these decisions are made at each and every device, including hosts. As networks are constructed and devices configured to forward packets and frames, network administrators must make critical decisions affecting performance, security, and optimization.

When moving to advanced ideas, the net admin should know how and why networking tables are constructed, and in what cases manual changes will be beneficial. This chapter provides details about the routing and switching operations, as well as design elements. This chapter assumes that the reader understands the basic operation of routers and switches, as well as the standard suite of protocols including Ethernet, Internet Protocol (IP), Address Resolution Protocol (ARP), and the Internet Control Message Protocol (ICMP).

Switching: Forwarding and Filtering Traffic

Most protocols are foregone conclusions, so when building networks, many of the choices are not choices at all. It is highly probable that a network will be a mixture of Ethernet and 802.11 nodes. ...