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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.