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CCNA Practical Studies: Gaining Access to Routers and Switches

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Learn how to access a router and switch through a direct console connection, over the LAN via Telnet, and finally through a terminal server.
This chapter is from the book

This chapter is from the book

This chapter describes how to access a router through the following methods:

  • Through a direct console connection
  • Over the LAN via Telnet
  • Through a terminal server

In this chapter, you learn how to access a router and switch through a direct console connection, over the LAN via Telnet, and finally through a terminal server. To begin, this chapter reviews how to access a router or switch through a direct console connection. Next, you will configure the terminal server router for Telnet access. Then you will access the terminal server over the LAN via Telnet using a terminal application program running on your PC. Finally, you will configure the 2511 router as the lab terminal server for reverse Telnet to access the lab routers.

Routers and switches can be accessed and configured through various means. To initially configure a Cisco device, you will need to connect directly through the console port. The console port exists on both routers and switches and is available to configure and monitor the device.

Direct Access to Routers and Switches Through a Console Port

Most Cisco devices use a rollover cable connected to the console port on the router or switch. For exceptions, consult the product documentation to verify whether you should use a straight-through or rollover cable. The cable is then connected to an RJ-45–to–DB-9 or RJ-45–to–DB-25 terminal adapter that is attached to a serial communications port (COM1, COM2, or other COM port) on the PC. Figure 4-1 shows how this is done.

Figure 4-1Figure 4-1

Connecting a Device with a Console Cable

When the physical connection is in place, configure the terminal application program on the PC with the following COM settings:

  • 9600 bps
  • 8 data bits
  • No parity
  • 1 stop bit
  • No flow control

In the lab, you will be using the terminal application program HyperTerminal to connect to the terminal server's console port. Any terminal application could be used based on your personal preference. If another terminal application is used, consult the product documentation for configuration and setup procedures.


The version of HyperTerminal has changed over the years to address functionality problems within the application. For example, older versions that came with Windows 95 and NT could not send the Ctrl-Break sequence (needed to break into the router). An early version that came with NT Service Pack 2 or 3 fixed this issue but had a problem when pasting several commands into the configuration script—it took about 5 seconds per line while it sent CPU utilization to 100 percent. The version that comes with NT-SP5, 98, and 2000 is fine. The authors of the program (Hilgraeve) provide a free update. To obtain the free update, open HyperTerminal, click Help, About, Upgrade Information, and then follow the upgrade instructions, or visit http://www.hilgraeve.com.

Let's demonstrate how this is done.
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