Cisco Catalyst switches represent the best selling LAN switching product in the world today. A wide range of switching platforms are offered, which offer switches for all types of networks and customers. Cisco switches are offered either in a fixed-configuration form factor or in a chassis-based form factor. The major operating systems used to manage Cisco switches include Cisco IOS and Catalyst OS (CatOS). Cisco IOS is the future operating system for all Catalyst switches; however, CatOS is still the prevalent Cisco Catalyst operating system today.
Placing a Cisco Catalyst switch onto a network consists of physically installing the switch and any associated hardware, powering on the switch and verifying all software and hardware is functioning as expected, and then configuring basic parameters such as switch identification, network management support, and date/time. Once your base configuration is in place, you can enable connectivity for Ethernet devices, allowing these devices to communicate via the switch.
Although the tasks described in this chapter are simple and might seem straightforward, problems do still occur with these configurations. One of the most common troubleshooting issues in LAN networks is the mismatch of speed/duplex settings, caused by either misconfiguration or auto-negotiation problems. These issues are typically hard to detect. Often connectivity is achieved; however, performance is poor, and errors are detected on the Ethernet interface. By understanding how auto-negotiation can cause mismatches and disabling auto-negotiation where possible, you should be able to eliminate these issues. When interconnecting Cisco devices, you can use Cisco Discovery Protocol (CDP) to find any devices that are locally connected. CDP is enabled by default and is independent of any Layer 3 protocol. By viewing CDP information, you can detect IP addressing misconfiguration and speed/duplex mismatches.