CCNA Lab 0 [Currently Being Updated]
Navigating with the command line / Configuration modes
Viewing and saving your configuration
Clearing previous configurations
The purpose of this lab is to familiarize you with the basic configuration of Cisco IOS devices.
You will learn the different configuration modes and how to move between them. You will learn the no command and how to negate previous commands. Viewing, saving, and deleting configurations will also be covered.
Do not worry about not fully understanding how everything works for this lab. This lab is merely to introduce you to the devices.
If you are using Poderosa, simply run the connecting script for your pod. This will connect you to every device, and label the tabs appropriately.
If you are using another telnet client, you need to connect to each device. The IP address to telnet to is 128.213.10.X where X is your pod number. Located at 128.213.10.X is a terminal access server that is connected to the console ports of each device. To connect to Router 1, telnet to 128.213.10.X port 2001. Router 2 is connected to port 2002, ect… Port numbers are show on the physical lab diagrams as red numbers in yellow boxes.
After connecting to your devices, you may be presented with something similar to the following.
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]: no
This is the default prompt that is presented anytime a Cisco IOS device boot with a default configuration. The initial configuration dialog is a fairly useless tool, and we will not be using it. It helps you set very basic configuration information in a very laborious way, and we will be teaching you how to do all of that using the command line. When prompted for this, type no. If asked if you would like to terminate auto install, simply press enter, accepting the default ‘Yes.’
After connecting to your pod, you should be presented with a prompt looking something like this on your routers:
Router>
And this on your switches:
Switch>
The > means that you are in user mode, and the Router / Switch is the hostname of that device. User mode has limited privileges and cannot make any configuration changes. To go from user mode to privileged mode, use the enable command.
Router>enable
Router#
If there is a password set, it will prompt you for one.
Router>enable
Password:
Router#
Privileged mode is denoted by a pound sign (#) after the hostname. To go from privilege mode to user mode, type exit.
Router#exit
Router con0 is now available
Press RETURN to get started.
Router>
Privilege mode is where you can access all information about a devices status. You can issue various show commands from privileged mode. To see a list of show commands available to you, use the show ? command.
Router#show ?
aaa Show AAA values
aal2 Show commands for AAL2
access-expression List access expression
access-lists List access lists
accounting Accounting data for active sessions
adjacency Adjacent nodes
alarm-interface Display information
about a specific Alarm
...
whoami Info on current tty line
wrr-queue WRR queue
x25 X.25 information
x28 X.28 rotary information
x29 X.29 information
xconnect xconnect information
xtagatm XTagATM information
zone Zone Information
zone-pair Zone pair information
There are hundreds of show commands available to you to verify, test, and diagnose your configuration. Some of these commands have multiple options as well. Use the show ip ? command to see a list of commands related to the IP configuration and status of the device.
Router#show ip ?
access-lists List IP access lists
accounting The active IP accounting database
admission Network Admission Control information
aliases IP alias table
arp IP ARP table
as-path-access-list List AS path access lists
auth-proxy Authentication Proxy information
...
ssh Information on SSH
tcp TCP/IP header-compression statistics
traffic IP protocol statistics
traffic-export Show ip traffic-export statistics
trigger-authentication Trigger-authentication host table
urlfilter IOS URL Filtering Information
virtual-reassembly IP Virtual Fragment Reassembly (VFR) information
vrf VPN Routing/Forwarding instance information
wccp WCCP information
We will only be covering a tiny subset of these commands in class. The question mark (?) is a very helpful tool on Cisco devices. It will give you a list of all commands that you can use in that mode. Its helpfulness cannot be emphasized enough. If you don’t know, or can’t remember the command to use for something, if is often helpful to use the question mark to see a list of available commands. It is also very helpful on Cisco certification exams when you can’t remember exactly the syntax of a command.
Cisco IOS devices store configuration information in two different file. One is the currently running configuration, stored in the running-config file, and the other is the startup configuration, stored in the startup-config file. On Cisco devices, any configuration changes that are made are made directly to the running-config file, and take effect immediately. When a router boots, it copies the contents of the startup-config to the running-config file. To view the contents the running configuration, use the show running-config, or show run command.
Router#show run
Building configuration...
Current configuration : 879 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 20
!
!
ip cef
!
!
!
!
voice-card 0
no dspfarm
!
!
!
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
no ip address
shutdown
no fair-queue
!
interface Serial0/0/1
no ip address
shutdown
clock rate 2000000
!
!
ip http server
no ip http secure-server
!
!
!
control-plane
!
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
!
end
Use the show startup-config or show start to see the boot config file.
To save your configuaration on the device, use the copy running-config startup-config or copy run start commands.
Router#copy run start
Destination filename [startup-config]?
Building configuration...
[OK]
Router#
This saves your configuration to the device for the next boot.
Some times when you start work on a pod there will already be a configuration from a previous student. Before starting any lab, or pasting in any previous configuration, you want to always clear the device. For routers, there is just one file that you want to erase, the startup-config file. To do this, use the erase startup-config command.
Router#erase startup-config
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]<ENTER>
[OK]
Erase of nvram: complete
Router#
*Aug 27 17:54:14.341: %SYS-7-NV_BLOCK_INIT: Initialized the geometry of nvram
Router#reload
Proceed with reload? [confirm]<ENTER>
For switches, you need to delete the vlan configuarion as well. To do this, use the delete vlan.dat command.
Switch#erase startup-config
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]<ENTER>
[OK]
Erase of nvram: complete
Switch#
1w4d: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvram
Switch#delete vlan.dat
Delete filename [vlan.dat]?<ENTER>
Delete flash:vlan.dat? [confirm]<ENTER>
Switch#reload
Proceed with reload? [confirm]<ENTER>
The devices are now cleared, and ready for you to begin the lab.