CCNA Part 10: CLI and SSH
Part 10 – SSH and CLI tips
Listing commands
When we wish to configure a router or switch, we obviously use commands but we may not know every command.
Connect to your router first in user mode
1. At the command prompt hold down shift + ?
2. You should now see a list of commands available in use mode
Router>?
Exec commands:
<1-99> Session number to resume
connect Open a terminal connection
disable Turn off privileged commands
disconnect Disconnect an existing network connection
enable Turn on privileged commands
exit Exit from the EXEC
logout Exit from the EXEC
ping Send echo messages
resume Resume an active network connection
show Show running system information
ssh Open a secure shell client connection
telnet Open a telnet connection
terminal Set terminal line parameters
traceroute Trace route to destination
3. Now type enable command for priviaged mode and now shift +?
Now you can see a lot more commands available to privilege mode
<1-99> Session number to resume
Auto Exec level Automation
clear Reset functions
clock Manage the system clock
configure Enter configuration mode
connect Open a terminal connection
copy Copy from one file to another
debug Debugging functions (see also ‘undebug’)
delete Delete a file
dir List files on a filesystem
disable Turn off privileged commands
disconnect Disconnect an existing network connection
enable Turn on privileged commands
erase Erase a filesystem
exit Exit from the EXEC
logout Exit from the EXEC
mkdir Create new directory
more Display the contents of a file
no Disable debugging informations
ping Send echo messages
reload Halt and perform a cold restart
reload Halt and perform a cold restart
resume Resume an active network connection
rmdir Remove existing directory
send Send a message to other tty lines
setup Run the SETUP command facility
show Show running system information
ssh Open a secure shell client connection
telnet Open a telnet connection
terminal Set terminal line parameters
traceroute Trace route to destination
undebug Disable debugging functions (see also ‘debug’)
vlan Configure VLAN parameters
write Write running configuration to memory, network, or terminal
To list a command quicker if you know the first letter or part of the command name you simply need to type the following
1. Type in the command prompt c?
Now the terminal will show you all possible commands begging with “C”
Router#c?
clear clock configure connect copy
Now if we want to be a little more specific we just need to specify more letters. For example if we know the first 3 letters of a command we can do the following:
1. Type in the command prompt con? Now you will be listed commands that begin with con
Router#con?
configure connect
When you are in configuration mode and wish to run a command that only works with privileged mode you can issue the do command, for example if you are in configuration mod but wish to run the show running-config which only works in privileged mode, simply use the do command.
Type do show running-config or short do show run
Enabling SSH and disabling Telnet.
1. Logon to your router > enable (privileged mode)
2. Go to config mode config t
3. Give your router a name if not already configured ip domain name robertwelsh.local
4. Type User
5. Type username robert password cisco
6. Type Crypto
7. Type Crypto key
8. Type Crypto key genet
9. Type crypto key generate rsa general-keys modulus 1024
10. Type crypto key generate rsa ? to see crypto commands
11. Last enable SSH v2, use the following command ip ssh version 2
12. Now we need to disable telnet line line vty 0 4
13. Type transport input ssh, now telnet is shutdown and ssh is enabled
14. Exit exit
15. Now we need to save the configuration, copy running config startup-config
Now test
Open your Putty client and first test login with telnet, should not work
Now try with SSH, you should be able to login, you will be presented with a certificate

When you login you will be asked for user and pass, its going to fail, this is because we need to set the local login.
1. Get to configuration mode config t and then type login local
2. Exit exit
3. Show running configuration
4. Finish.