Cisco Systems CCNA 2 Starting a Router, Initial startup of Cisco routers, Router LED indicators

2.2Starting a Router

Essential Labs:	2.2.1, 2.2.4, and 2.2.9
Optional Labs:	None
Core TIs:	All
Optional TIs:	none

Course-Level Claim: Students can describe the purpose and fundamental operation of the router IOS

Certification-Level Claim: Students can establish communication between a terminal device and the router IOS and use it for system analysis, configuration, and repair

Hands-on skills: none

2.2.1 Initial startup of Cisco routers

This section teaches students about the startup process for a router. Students learn how to establish a HyperTerminal session and log into a router. Students will then be introduced to the help feature and enhanced editing commands.

When a Cisco router powers up, it performs a POST. This executes diagnostics from ROM on all hardware modules. After the POST, the following events occur as the router initializes:

•Bootstrap is loaded from ROM.

•IOS is loaded from flash, TFTP, or ROM.

•Config is loaded from NVRAM or TFTP into setup mode.

This section teaches students how to check the configuration during the boot process. Setup mode is intended to quickly install a router with minimal configuration. Discuss the initial startup of routers and explain why the IOS and configuration files can be loaded from several places.

2.2.2 Router LED indicators

Router LED indicators indicate the status of a router. If an interface is extremely busy, its LED will be on all the time. The green LED will be on after the router card initializes correctly.

Have the students view the LED indicators on the routers in the lab setup. Show them LEDs that work correctly and explain what they are. Make sure the students understand that the port status and link LEDs are the prime indicators of the physical layer status.

2.2.3 The initial router bootup

Bootup messages displayed by a router include messages such as “NVRAM invalid, possibly due to write erase”, which indicates that the router has not been configured or the backup configuration has been erased.

21 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 2 Copyright ♥ 2004, Cisco Systems, Inc.