Networking

Router Configuration 101: Setting up the router

Whether it's been years since you've worked with routers or you're just starting out, it never hurts to review the basics. In the first part of our three-part series, find out how to boot up your new Cisco router, and learn about the various router modes.

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I recently heard from a member who asked me to explain how to configure a router from scratch. To answer his question, I decided to address Cisco router configuration in a three-part series.

Whether it's been years since you've worked with routers or you're just starting out, it never hurts to review the basics—even if you're a seasoned administrator. Sometimes we get so used to our way of doing things that we fail to recognize the shortcuts we take on a regular basis.

People tend to worry more about configuring a Cisco router because it's not a Netgear, Linksys, or D-Link router that they'd find at their local Best Buy. Unlike consumer routers that have a single application (i.e., connecting you to the Internet), a business-class Cisco router (such as the older 1700, 2600, and 3600 series or the newer 1800, 2800, and 3800 series) has seemingly unlimited applications. However, this limitless use makes Cisco routers inherently more difficult to configure.

Of course, we can't possibly address all of the potential applications for these routers, even in three articles. Therefore, in this series, we'll focus on booting up the router, applying basic configuration, and connecting to the Internet.

Getting started

Let's start at the beginning.

  1. Hook up the power cable to the router.
  2. Connect the serial console cable from the router's console port (RJ-45) to the back of a PC or laptop (DB-9 Serial, "COM1 Port").
  3. Because HyperTerminal comes with Windows, many people use it to configure Cisco routers. To open HyperTerminal from Windows, go to Start | Programs | Accessories | Communications | HyperTerminal.
  4. Create a new connection called Cisco, click OK to accept the default of using COM1, change the baud rate to 9600 baud on the Serial Port settings, and click OK, which should take you to the router's console.
  5. Power-on the router, and watch the boot-up sequence. Listing A shows a sample boot-up sequence of a 2600 series router.
  6. Following the prompt, press [Enter]. Because it's a new router, you'll automatically go into Setup Mode. You should see something like this:
         --- System Configuration Dialog ---
Continue with configuration dialog? [yes/no]:

Setup Mode asks you a series of questions to assist you in configuring the router. While this is helpful for beginners, it doesn't really teach you how to configure the router. For our purposes, enter n, and press [Enter].

Want to learn more about router and switch management? Automatically sign up for our free Cisco Routers and Switches newsletter, delivered each Friday!

I recently heard from a member who asked me to explain how to configure a router from scratch. To answer his question, I decided to address Cisco router configuration in a three-part series.

Whether it's been years since you've worked with routers or you're just starting out, it never hurts to review the basics—even if you're a seasoned administrator. Sometimes we get so used to our way of doing things that we fail to recognize the shortcuts we take on a regular basis.

People tend to worry more about configuring a Cisco router because it's not a Netgear, Linksys, or D-Link router that they'd find at their local Best Buy. Unlike consumer routers that have a single application (i.e., connecting you to the Internet), a business-class Cisco router (such as the older 1700, 2600, and 3600 series or the newer 1800, 2800, and 3800 series) has seemingly unlimited applications. However, this limitless use makes Cisco routers inherently more difficult to configure.

Of course, we can't possibly address all of the potential applications for these routers, even in three articles. Therefore, in this series, we'll focus on booting up the router, applying basic configuration, and connecting to the Internet.

Getting started

Let's start at the beginning.

  1. Hook up the power cable to the router.
  2. Connect the serial console cable from the router's console port (RJ-45) to the back of a PC or laptop (DB-9 Serial, "COM1 Port").
  3. Because HyperTerminal comes with Windows, many people use it to configure Cisco routers. To open HyperTerminal from Windows, go to Start | Programs | Accessories | Communications | HyperTerminal.
  4. Create a new connection called Cisco, click OK to accept the default of using COM1, change the baud rate to 9600 baud on the Serial Port settings, and click OK, which should take you to the router's console.
  5. Power-on the router, and watch the boot-up sequence. Listing A shows a sample boot-up sequence of a 2600 series router.
  6. Following the prompt, press [Enter]. Because it's a new router, you'll automatically go into Setup Mode. You should see something like this:
         --- System Configuration Dialog ---
Continue with configuration dialog? [yes/no]:

Setup Mode asks you a series of questions to assist you in configuring the router. While this is helpful for beginners, it doesn't really teach you how to configure the router. For our purposes, enter n, and press [Enter].

Learning your way around router modes

This takes you to the router> prompt, which means you're in User Mode. You can identify User Mode by the [>] at the end of the prompt. However, you really can't accomplish anything useful in User Mode, so enter enable and press [Enter] to go to Privileged Mode.

Once in Privileged Mode, you should see the router# prompt. Like the [>] indicator for User Mode, [#] at the end of the prompt indicates that you are in Privileged Mode. This is equivalent to the Administrator account in Windows.

However, you can only view things when in Privileged Mode—you can't change anything. To change something, you must be in Global Configuration Mode. To get to this mode, enter configure terminal, and press [Enter]. The prompt should now say router(config)#.

Figure A offers a graphical display of navigating the various router modes.

Figure A

Stay tuned: Next time, we'll discuss how to perform basic configuration on the router.

David Davis has worked in the IT industry for 12 years and holds several certifications, including CCIE, MCSE+I, CISSP, CCNA, CCDA, and CCNP. He currently manages a group of systems/network administrators for a privately owned retail company and performs networking/systems consulting on a part-time basis.

Learning your way around router modes

This takes you to the router> prompt, which means you're in User Mode. You can identify User Mode by the [>] at the end of the prompt. However, you really can't accomplish anything useful in User Mode, so enter enable and press [Enter] to go to Privileged Mode.

Once in Privileged Mode, you should see the router# prompt. Like the [>] indicator for User Mode, [#] at the end of the prompt indicates that you are in Privileged Mode. This is equivalent to the Administrator account in Windows.

However, you can only view things when in Privileged Mode—you can't change anything. To change something, you must be in Global Configuration Mode. To get to this mode, enter configure terminal, and press [Enter]. The prompt should now say router(config)#.

Figure A offers a graphical display of navigating the various router modes.

Figure A

Stay tuned: Next time, we'll discuss how to perform basic configuration on the router.

David Davis has worked in the IT industry for 12 years and holds several certifications, including CCIE, MCSE+I, CISSP, CCNA, CCDA, and CCNP. He currently manages a group of systems/network administrators for a privately owned retail company and performs networking/systems consulting on a part-time basis.

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