Cable Descriptions
Introduction      Requirements      RJ-45 Cable Types           Identify an RJ-45 Cable           Straight-Through Cable           Crossover Cable           Rolled Cable           Console Cable           Adapters      Select the Correct Cable      Related Information	Download PDF   Cable Descriptions

Introduction

This document explains how to use different types of cables with Cisco equipment.

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Requirements

There are no additional requirements for this document.

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RJ-45 Cable Types

Cisco products use these RJ-45 cable types:

• Straight-through

• Crossover

• Rolled

• Console

Straight-through, crossover, and rolled cables look identical but are wired differently. For information about each cable type, see Identify an RJ-45 Cable.

For information on how to choose the right cable, see Select the Correct Cable.

Identify an RJ-45 Cable

To identify the RJ-45 cable type, hold the connectors together so you can see the colored wires, as shown in the picture.

Examine the sequence of colored wires to determine the type of RJ-45 cable. There are four types of commonly used RJ-45 cables: straight-through, crossover, rolled, and console.

Straight-Through Cable

A straight-through cable contains colored wires in the same sequence at both ends of the cable. Straight-through cables are the most common RJ-45 cable and are used to connect network devices to an Ethernet switch.

To learn how you can use a straight-through cable, see Select the Correct Cable.

Crossover Cable

A crossover cable has four colored wires that are in reverse sequence on each end of the cable. Wires 1 and 3 and wires 2 and 6 are at opposite positions on each side of the cable. Crossover cables commonly connect two Ethernet devices.

To learn how you can use a crossover cable, see Select the Correct Cable.

Rolled Cable

A rolled cable contains wires that are in reverse sequence at each end of the cable. Rolled cables commonly connect digital telephones, ISDN, T1, and serial RS-232 devices.

Note: Rolled cables allow you to manage your Cisco device. You need an adapter to use a rolled cable to connect your PC to a Cisco device. See Adapters for more information.

Console Cable

The console cable allows you to access your Cisco device directly in order to make configuration changes or troubleshoot problems. A console cable has RJ-45 and DB-9 female connectors and is also known as a management cable.

The console cable connects the serial port of your PC to the console port of your Cisco device. This example uses a Cisco 800 series router.

You can then create a console connection from your PC to the Cisco device with terminal emulation software such as HyperTerminal. For additional information on how to create a console connection, refer to Create a HyperTerminal Connection.

Adapters

Adapters allow you to use cables with different types of ports. There are two types of adapters: RJ-45 to DB-9 and RJ-45 to DB-25.

Adapters allow you to:

• Covert a rolled cable from RJ-45 to DB-9. This allows you to use a rolled cable as a console cable.

• Convert a cable with a DB-9 connector to DB-25. This allows you to create a console connection to a computer with an older DB-25 serial port.

For more information on how to create a console connection, refer to Create a HyperTerminal Connection.

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Select the Correct Cable

Crossover and straight-through cables are used to connect network devices. Use the table to match the two devices you want to connect to determine which cable you need.

Note: Router includes devices such as Cisco Access Points and PIX Security Appliances.

Note: To create a console connection between your PC and a Cisco device, see the Console Cable section.

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Related Information

• Create a HyperTerminal Connection
• Configure an IP Address on Your PC
• Set Up a TFTP Server