Lab 3 Routing Information Protocol RIPv1 on a Cisco Router Network CMPE 150 Fall 2005 Introduction Today you are going to be thrown into using Cisco s Internetwork Operating System IOS to configure three routers in a simple network topology Unlike switches routers are not very plug and play and require network planning to set up Most of the planning has been done for you in this lab and it s up to you to do the rest To route packets among the networks RIPv1 will be used A short description of RIP follows RIP background Due to time constraints you have today I will spare you long details on RIP but I will include a small excerpt from the RIPv1 RFC 1058 RIP is one of a class of algorithms known as distance vector algorithms The earliest description of this class of algorithms known to the author is in Ford and Fulkerson 6 Because of this they are sometimes known as Ford Fulkerson algorithms The term Bellman Ford is also used It comes from the fact that the formulation is based on Bellman s equation the basis of dynamic programming Getting Started with the Router and IOS Internetwork OS Step 1 Connecting to the Console port Patch your computer s serial port to the router you are working on with a straight through Cat5 cable all the cables in the lab except the orange ones are straight through Refer to Appendix A 1 to figure out which computer will patch to which router Appendix A 4 to figure out which port on the patch panels is connected to your computer s serial port and Appendix A 3 to figure out which port on the router connects to the serial port of your PC Step 2 Running Minicom a standard terminal emulator to communicate with and configure the router To start Minicom on your Linux machine type minicom in a terminal window The router s console port is connected to COM 1 of your computer and uses 9600 baud 8 data bits no parity 1 stop bit and no flow control If you don t manage to communicate with the router make sure your Minicom settings are correct To access the menu in Minicom press Ctrl A and then Z Step 3 Bypassing Setup Mode At this point your host should have a console session with the Router Since these routers may or may not have a pre existing configuration what you see after pressing the Enter key may vary Possibility 1 After several lines of information on the screen you should eventually see Would you like to enter the initial configuration dialog yes no n If you see such a message the router is ready to enter Setup Mode For now if you are being prompted to answer a question answer n and press return If you accidentally press y and enter Setup Mode press and hold down the control key and press C CTRL C Wait a few seconds and then press Enter On some routers you may see the following message Would you like to terminate autoinstall yes no y Type y or yes to terminate autoinstall You should eventually see the router prompt Router Go to Step 4 Possibility 2 You may see a router prompt similar to this example Router If you see a prompt ending in the someone has saved a configuration on the router startupconfig Because it is always best to begin our labs without a previous router configuration you will need to erase the startup config and reboot the router Router enable Router erase startup config Turn off the router and then turn it back on or type reload Go to Possibility 1 Step 4 Basic Commands You should now be at the User Mode with the prompt Router User mode will allow you to view the state of the router but will not allow you to modify its configuration Using help Use the to view the list of available commands or command options Router a Press the Space Bar to scroll a screen s worth of more commands b Press the Enter or Return key to scroll down just one line of the list c Press any other key to halt the list output Router show Displays the next parameter or parameters that can be used with this command Router show interface Displays the next parameter or parameters that can be used with this command Try some others Privilege Mode Now lets enter Privilege Mode or enable mode which does allow you to modify the router s configuration Router enable Note On a production router and in our labs there would be a privilege password set where you would have to give the correct password before being able to enter privilege mode Notice how the prompt changes Router disable This will take you back to User Mode Router enable This will take us back to Privilege Mode Router exit Exits the user out of User Mode more later Router Notice how many more commands are available to you in Privilege Mode Any commands entered from User Mode can also be entered from Privilege Mode However not all Privilege Mode commands can be entered in User Mode Using Help and Setting the Clock Router clock set Use the clock set command along with the help to give you the commands the router IOS is expecting Notice that it leaves the part of the command you already have included Continue with this command until you have successfully changed the time and date Router show clock Verify the time and date Abbreviated commands The Cisco IOS will allow you to abbreviate any command or parameter as long as it uniquely identifies the command or parameter Router sh inter Instead of show interface Viewing the configuration To view the current configuration of the router which resides in RAM known as the runningconfig Router show running config You will notice that this contains the actual commands that are either default commands or were used to configure the router When you make changes to the router those changes are stored in the running config file Router show startup config This will show the saved configuration in NVRAM If the running configuration has not been saved the startup config file will be empty Router copy running config startup config This will copy the current running config file in RAM to the startup config file in NVRAM Now if the router is rebooted or loses power and powered back up the changes you made to the router have been saved The startup config is copied to the running config during the reboot process Router copy run start This is an example of abbreviating a command BE CAREFUL Do NOT abbreviate the file names incorrectly i e copy running start up as that will have a different affect on the router in this case overwrite the IOS in flash later Router show startup config Router show running config Notice that the running config and the startup config are identical Erasing the saved
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