Basic Device Configuration

Hostname

Router (config) # hostname R1 / host R1

Disable DNS Lookup

Router (config) # no ip domain-lookup / no ip domain-look

Encrypt Plaintext Passwords

Router (config) # service pass-encryption / service pass

Privileged Exec Password

Router (config) # enable secret class / enable sec class


Console

Router (config) # line console 0 / line con 0
Router (config-line) # password cisco / pass cisco
Router (config-line) # login
Router (config-line) # logging synchronous / logging syn
Router (config-line) # no exec (optional to disable console timeout to avoid hassle of re-entering passwords)
Router (config-line) # exit


VTY

Router (config) # line vty 0 15
Router (config-line) # password cisco / pass cisco
Router (config-line) # login
Router (config-line) # logging synchronous / logging syn
Router (config-line) # exit


Banner

Router (config) # banner motd #For Authorised Access Only#


Saving Running Configuration to Startup-Configuration

Router # copy running-config startup-config / copy run start / write mem / write / wr
(Note: wr is the fastest as it saves you the hassle to choose Y/N after executing a copy run start command)


Do Command

This command allows you to execute from a higher configuration level.

For example:

Router (config) # end
Router # write

You can simply do this to save you the hassle to exit or end from higher level:
Router (config) # do wr


Show Running Configuration

R1 # show running-config

or from other level
R1 (config-router) # do sh ru