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Module 6 : Summary

Summary
This page summarizes the topics discussed in this module.
Switches are similar to routers. They have basic computer components including a CPU, RAM, and an operating system. There are several ports that are used to connect hosts and for management. LEDs on the front of the switch show the system status, RPS, port mode, and port status. When powered on, a switch performs POST automatically to verify that the switch functions correctly. HyperTerminal can be used to configure or check the status of a switch.
Another similarity to Cisco routers is the CLI. Enter a question mark (?) to access help. A list of available commands will display. Switches provide word help and command syntax help.
Switches and routers have the same command modes. User EXEC is the default and is indicated by the greater-than character (>). The enable command changes User EXEC to Privileged EXEC as indicated by the pound sign (#). Access to Privileged EXEC mode should be password protected to prevent unauthorized use. The configure command allows other command modes to be accessed.
Default data is provided when the switch is powered up for the first time. For management purposes, a switch is assigned an IP address. Use the show version command to verify the IOS version and the configuration register settings.
Once a switch is configured with an IP address and gateway, it can be accessed through a web-based interface. This allows for the configuration and management of the switch. This service can be accessed through a web browser with the IP address and port 80, the default port for http.
A switch dynamically learns and maintains thousands of MAC addresses. If frames with a previously learned address are not received, the MAC address entry is automatically discarded or aged out after 300 seconds. The command clear mac-address-table entered in the Privileged EXEC mode can be used to manually clear address tables.
A permanent MAC address assigned to an interface ensures that the MAC address will not be aged out automatically by the switch and to enhance security. The command mac-address-table static <mac-address of host > interface FastEthernet <Ethernet number > vlan <vlan name > can be used to configure a static MAC address. Use the no form of the command to remove it. The command show port security can be used to verify port security.
The switch name, IP address, default gateway, and line passwords should be configured on a new switch that is added to a network. When a host is moved from one port or switched to another, configurations that can cause unexpected behavior should be removed. Documentation should be maintained for the current configuration and backups to the server or a disk should be performed periodically. 

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