Chapter 6 began with a look at the external features of a Cisco 2500 series router. This included an overview of each port, including its numbering, physical connectors, and characteristics. An overview of the router’s Ethernet port provided insight into AUI connections, transceivers, and their purpose.
A closer look a router’s serial ports included an explanation of synchronous communications, DTE and DCE devices, and the physical layer communications standards that are used to connect between these devices. A basic introduction to CSU/DSUs provided insight into its role in the WAN communication process.
The purpose of both the asynchronous console and auxiliary ports was looked at next, including the ways in which these ports are connected to devices using rollover cables and adapters. The pinouts for a rollover cable were also looked at, in order to allow you to create your own as necessary. A review of the router’s LED lights provided insight into the types of information that these provide.
A look at a router’s internal elements focused on the four main memory storage areas used on Cisco routers, including Flash, RAM, ROM, and NVRAM. The information contained within each was examined, as were their associated characteristics.
An overview of the Cisco IOS provided insight into features sets and the different types of IOS releases provided by Cisco. The ability to distinguish a major release from an early deployment release was discussed, as were the purposes of maintenance and general deployment releases.
