Configuring a Router MM Clements
Copyright This Week Command line interface Router configuration Modes for configuration Interface configuration Working with configurations using Packet Tracer 5.x
Copyright Conventions used in these notes All commands e.g. enable will use Courier font to distinguish them from text After each command has been entered you should press Enter (Return)
Copyright Cisco IOS Internetwork Operating System Accessed via command line only No GUI – makes for increased OS reliability and lower hardware requirements Has modes for operation unlike Linux or DOS
Copyright Command-Line Interface Modes
Copyright Global Configuration Modes
Copyright Initial login to a router Power up router System information displayed Begins in User Executive mode Users can do little (damage!) here Enter Privileged Executive mode with enable command May be password protected User will be prompted if necessary
Copyright Router Boot Process Router decompresses IOS image from Flash memory Legal information is displayed On first ever ( or clean ) boot, user is asked whether or not to enter configuration dialogue This is for non-Cisco educated people – answer n ( for NO )
Copyright System Bootstrap, Version 12.1(3r)T2, RELEASE SOFTWARE (fc1) Copyright (c) 2000 by cisco Systems, Inc. cisco 2620 (MPC860) processor (revision 0x200) with 60416K/5120K bytes of memory Self decompressing the image : ######################################################################### # [OK] Restricted Rights Legend Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c) of the Commercial Computer Software - Restricted Rights clause at FAR sec and subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software clause at DFARS sec Cisco Systems, Inc. 170 West Tasman Drive San Jose, California
Copyright Clean Boot Continued --- System Configuration Dialog --- Continue with configuration dialog? [yes/no]: n Press RETURN to get started! Router>? Exec commands: 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 Etc. etc.
Copyright Learning the Commands Unlike Linux and DOS, all commands available can be accessed using a question mark ( ? ) – displays minor help too This allows all or partially typed commands to be shown E.g. to show all commands that begin with the letter ‘c’ type c? at the prompt and press enter (return)
Copyright Getting Going In User Exec the prompt is Router> From User Exec proceed to Privileged Exec using the enable command Now you are in Privileged Exec the prompt is Router# This mode allows many parameters of the router to be viewed These can be seen using a show command
Copyright Examining the show Commands There are many show commands that display the settings for the router – Also useful for troubleshooting In both Privileged EXEC and User EXEC modes, the command show ? provides a list of available show commands
Copyright Making Changes to the Router To change settings you need to enter Global Configuration mode This can be achieved using the configure terminal command The prompt now changes to Router(config)# A different set of commands are now available Many configuration modes exist too
Copyright Configuring a Router Name A router should have a name to allow it to be easily identified The location is a good choice but any name can be set Router(config)#hostname Chatham Chatham(config)# The router’s security should be considered too
Copyright Router Identification Configuration
Copyright Password Configuration
Copyright Configuring an Ethernet Interface 1. Enter global configuration mode 2. Enter interface configuration mode 3. Specify the interface address and subnet mask 4. Enable the interface
Copyright Setting FastEthernet Interface Router(config)#interface FastEthernet 0/0 Router(config-if)#ip address Router(config-if)#no shutdown %LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up Router(config-if)#
Copyright What interfaces does the router have? You need to use a show command show ip interface brief will list all interfaces of the router The names of the interfaces must be entered to make changes to the interfaces of the router
Copyright Router#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 unassigned YES unset administratively down down FastEthernet0/1 unassigned YES unset administratively down down Serial0/0 unassigned YES unset administratively down down Serial0/1 unassigned YES unset administratively down down
Copyright Interface Configuration Commands
Copyright Interface Descriptions An interface description should be used to identify important information such as a distant router, a circuit number, or a specific network segment.
Copyright Adds, Moves, and Changes
Copyright Finishing the Configuration Once finished you should type the exit command to return one step back in the command mode structure To immediately return to Priv Exec, type the end command Now you need to save the configuration or if power is lost, the configuration is lost
Copyright Saving the Configuration When in Global Config mode, you are writing directly to DRAM The contents of DRAM can be accessed using the running-config file but are lost if the power is turned off The Priv Exec command copy running- config startup-config saves the contents of DRAM to NVRAM for the next reboot
Copyright Checking you have saved properly After issuing the copy running-config startup-config hcommand the router displays the following Router#copy running-config startup-config Destination filename [startup-config]? Building configuration... [OK] Router#
Copyright Rebooting the router At Priv Exec prompt, issue the reload command and confirm (Enter) The router restarts but no longer displays the same question about initial configuration You should be able see all of the information that you entered when in Priv Exec again Type the show running-config command and examine the output
Copyright Conclusion Cisco IOS allows command line modification A ? allows commands to be displayed CLI has modes for configuration Need to be in the right mode to make changes running-config file is the contents of DRAM startup-config file is used to store router’s configuration for the next boot