32 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 3 Copyright © 2004, Cisco Systems, Inc.
• Remove the startup configuration file with the erase startup-config
command.
• Restart the router and enter setup mode.
To save the configuration variables to the startup configuration file in NVRAM, enter the
following command at the privileged EXEC prompt:
Router#copy running-config startup-config
Students must understand that any changes that are made to the configuration will occur
immediately. These changes are made to the running configuration. Students must also
realize that configuration changes need to be saved to the startup configuration. If they are
not, then they will be lost when the router is restarted. Students should shut down interfaces
during configuration and enable the interface after the configuration changes are completed.
Ask students the following questions:
• Which command will erase the configuration file in NVRAM?
• Which command will erase the configuration file in RAM?
• Which command will copy the RAM to NVRAM?
• Which command will copy the NRAM to RAM?
3.1.7 Configuring an Ethernet interface
An Ethernet interface can be configured from the console or a virtual terminal line. By default,
interfaces are disabled. Use the no shutdown command to enable an interface. Use the
shutdown command to turn off an interface if it needs to be disabled for maintenance or
troubleshooting. The following command is used to configure interface serial 0/0. The interface
will change to up. Both ends of the serial cable need to be configured for the interface to stay
in an up state:
rt1(config)#interface serial 0/0
rt1(config-if)#ip address 192.168.0.1 255.255.255.0
rt1(config-if)#no shutdown
00:20:46: %LINK-3-UPDOWN: Interface Serial0/0, changed state to
up
00:20:47: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Serial0/0, changed state to up
rt1(config-if)#