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Cisco 7000 Series Routers

Cabling Guide for Console and AUX Ports

Cisco - Cabling Guide for Console and AUX Ports

Introduction

This document summarizes the cabling requirements for console and auxiliary (AUX) ports. Cisco routers either have RJ-45-based or DB-25 DCE/DTE console and AUX ports. You can connect either a terminal (DTE) or a modem (DCE) to these ports. In either instance, you need both an RJ-45 cable and an RJ-45-to-DB-25 or RJ-45-to-DB-9 connector.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document is not restricted to specific software and hardware versions.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Table of Routers with Console and AUX Ports

The table in this section lists the Cisco router series and the corresponding console and AUX ports.

Router Console Port Console Port Cable AUX Port AUX Port Cable
600 RJ-45 (management port) RJ-45 Rolled / RJ-45 to DB-9 Female N/A N/A
700 RJ-45 RJ-45 Rolled N/A N/A
800 RJ-45 RJ-45 Rolled / RJ-45 to DB-9 Female N/A N/A
1000 RJ-45 RJ-45 Rolled N/A N/A
1600 RJ-45 RJ-45 Rolled / RJ-45 to DB-9 Female N/A N/A
1700 RJ-45 RJ-45 Rolled / RJ-45 to DB-9 Female RJ-45 RJ-45 Rolled
2500 RJ-45 RJ-45 Rolled RJ-45 RJ-45 Rolled
2600 RJ-45 RJ-45 Rolled RJ-45 RJ-45 Rolled
3600 RJ-45 RJ-45 Rolled RJ-45 RJ-45 Rolled
MC3810 RJ-45 RJ-45 Rolled RJ-45 RJ-45 Rolled
4000 DB-25 DCE RS 232 / RJ-45 Rolled DB-25 DTE RS 232 / RJ-45 Rolled
AS5200/5300 RJ45 RJ-45 Rolled RJ-45 RJ-45 Rolled
AS5400 RJ-45 RJ-45 Rolled RJ-45 RJ-45 Rolled
AS5800 DB-25 DCE RS 232 / RJ-45 Rolled DB-25 DTE RS 232 / RJ-45 Rolled
7100/7200/7300 RJ-45 RJ-45 Rolled RJ-45 RJ-45 Rolled
7200 DB-25 DCE RS 232 / RJ-45 Rolled DB-25 DTE RS 232 / RJ-45 Rolled
7500 DB-25 DCE RS 232 / RJ-45 Rolled DB-25 DTE RS 232 / RJ-45 Rolled
12000 DB-25 DCE RS 232 / RJ-45 Rolled DB-25 DTE RS 232 / RJ-45 Rolled

Console Port Settings for Terminal Connection

Before you connect a terminal to the console port, configure the terminal to match the router console port as shown here:

  • 9600 baud

  • 8 data bits

  • no parity

  • 2 stop bits (9600 8N2) OR 1 stop bit

    Dependant on the router.

Types of Console and AUX Connectors

Cisco routers have three types of console and AUX connectors. The table in this section lists these types:

  • RJ-45

  • DB-25 DCE

  • DB-25 DTE

There are three styles of RJ-45-to-DB-25 connectors:

  1. DCE style (modem)

  2. DTE style

  3. DCE style (non modem)

Each of these styles has a different role. Generally, DTE is for terminals, DCE (modem) is for modems, and DCE (non-modem) is obsolete.

Note: Move pin 6 to pin 8 if you want to change a DCE style (non modem) to a DCE style (modem).

Console and AUX Connectors for Cisco Routers

Connector Graphic
RJ-45

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DB-25 DCE

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DB-25 DTE

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Cabling for console and AUX port:

Types of RJ-45 Cabling

Cisco products use these types of RJ-45 cables:

Cisco does not provide these cables. These cables are widely available from other sources. Console cable is usually provided with the Console Cable Kit.

Note: The console port does not support modem control or hardware flow control.

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How to Identify an RJ-45 Cable

In order to identify the RJ-45 cable type, hold the two ends of the cable next to one another so you can see the colored wires inside the ends, as shown here:

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There are three types of commonly used RJ-45 cabling: straight, cross and rolled. Hold the two ends of an RJ-45 cable side by side. There are eight colored strips, or pins, at each end. If the order of the colored pins is the same at each end, the cable is straight. If the order of the colors is reversed at each end, the cable is rolled.

Examine the sequence of colored wires to determine the type of RJ-45 cable. This section explains how you can do this.

Straight-through Cable

In a straight-through cable, the colored wires are in the same sequence at both ends of the cable.

Straight-through Cable

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RJ-45 Straight-through (Ethernet) Cable Pin-outs

Signal RJ-45 Pin RJ-45 Pin Signal
Tx+ 1 1 Tx+
Tx– 2 2 Tx–
Rx+ 3 3 Rx+
4 4
5 5
Rx– 6 6 Rx–
7 7
8 8

Crossover Cable

In a crossover cable, the first (far left) colored wire at one end of the cable is the third colored wire at the other end of the cable.

Crossover Cable

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RJ-45 Crossover (Ethernet) Cable Pin-outs

Signal RJ-45 Pin RJ-45 Pin Signal
Tx+ 1 3 Rx+
Tx– 2 6 Rx–
Rx+ 3 1 Tx+
4 4
5 5
Rx– 6 2 Tx–
7 7
8 8

Rolled Cable

In a rolled cable, the colored wires at one end of the cable are in the reverse sequence of the colored wires at the other end of the cable.

Rolled Cable

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Rolled Cable Pinouts

Signal RJ-45 Pin RJ-45 Pin Signal
1 8
2 7
3 6
4 5
5 4
6 3
7 2
8 1

Note: CAB-OCTAL-ASYNC, the 8-port RJ-45 adapter that is used with the Cisco 2509, 2510, 2511, and 2512, is the same as a rolled cable.

RJ-45 to DB-9 Female*

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This cable is also known as Management Cable.

*Cisco provides this cable with the 600, 800, 1600 and 1700 Series Routers.

Type of Cable for DB-25 Connectors

RS 232 Straight-through Cable

This illustration shows serial cable CAB-R23= (part number 74-0173), which is a general serial cable for all router platforms:

Both Ends of RS 232 Straight-through Cable for DB-25 Connectors

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This cable has a female DB-25 connector on one end and a male DB-25 connector on the other end. Either end of the CAB-R23 cable can be the Cisco end or the network end, depending on whether the Cisco router is designated as a DCE device or a DTE device. If the router is designated as a DCE device, the female DB-25 connector is the Cisco end. If the router is designated as a DTE device, the male DB-25 connector is the Cisco end.

Pin-outs for RS 232 Straight Through Cable (DB-25)

Male DTE Pin-outs Female DTE Pin-outs
25 Pin Signal 25 Pin Signal
   
J2-1 Shield GND J2-1 Shield GND
J2-2 Shield TxD – J2-2 Shield TxD –
J2-3 Shield RxD – J2-3 Shield RxD –
J2-4 Shield RTS – J2-4 Shield RTS –
J2-5 Shield CTS – J2-5 Shield CTS –
J2-6 Shield DSR – J2-6 Shield DSR –
J2-7 Shield Circuit GND – J2-7 Shield Circuit GND
J2-8 Shield DCD – J2-8 Shield DCD –
J2-15 Shield TxC – J2-15 Shield TxC –
J2-17 Shield RxC – J2-17 Shield RxC –
J2-18 Shield LTST – J2-18 Shield LTST –
J2-20 Shield DTR – J2-20 Shield DTR –
J2-24 Shield TxCE – J2-24 Shield TxCE –

Adapters

You need two types of adapters to connect a PC to a router.

  • RJ-45-to-DB-9 Adapter

  • RJ-45-to-DB-25 Adapter

RJ-45-to-DB-9 Adapter

This adapter connects a router to a PC though a COM port.

RJ-45-to-DB-9 Adapter

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RJ-45-to-DB-25 Adapter

This adapter connects a router to PC through a serial port.

RJ-45-to-DB-25 Adapter

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Cabling and Adapter Setups that Work

Here are the most common ways to console into a router.

Console Connection Combination

Console Port Cable Adapter for PC Adapter for Console Port
RJ-45 RJ-45 Rolled DB-9 / DB-25 None

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DB-25 DCE RJ-45 Rolled DB-9 / DB-25 RJ-45-to-DB-25

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DB-25 DCE DB-25 None None

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RJ-45 RJ-45-to-DB-9 None None

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Cisco provides this cable with the Cisco 600, 800, 1600 and 1700 Series Routers.

You cannot mix and match these components randomly. Here are the combinations that work:

Console Connection Combination

Port RJ-45 Cable DB-25 Adapter To Attach
AUX / Console Straight DCE non-modem TERMINAL
AUX / Console Rolled DTE TERMINAL
AUX / Console Rolled DCE modem MODEM
AUX / Console RJ-45-to-DB9 None TERMINAL

These are the only setups that work. If you do not have the components you need, use the RJ-45 Component Guide chart to order them.

RJ-45 Port and Adapter Pin-outs

This chart shows the pin-outs for RJ-45 console and AUX ports. The console port does not use RTS/CTS.

RJ-45 Port Pin-outs

Signal Console Port (DTE) RJ-45 Rolled Cable Adapter Adapter Signal
  RJ-45 RJ-45 Pin DB-9 Pin DB-25 Pin  
CTS 1 8 7 4 RTS
DTR 2 7 4 20 DSR
TxD 3 6 3 2 RxD
GND 4 5 5 7 GND
GND 5 4 5 7 GND
RxD 6 3 2 3 TxD
DSR 7 2 6 8 DTR
RTS 8 1 8 5 CTS

DB-25 Console and AUX Port Pin-outs

Console Port Signals

Pin Signal Direction Description
1 GND Ground
2 TxD <-- Transmit Data
3 RxD --> Receive Data
6 DSR --> Data Set Ready (always on)
7 GND Ground
8 DCD --> Data Carrier Detect (always on)

Note: The console port does not support modem control or hardware flow control.

Auxiliary Port Signals

Pin Signal Direction Description
2 TxD --> Transmit Data
3 RxD <-- Receive Data
4 RTS --> Request To Send (used for hardware control)
5 CTS <-- Clear To Send (used for hardware flow control)
6 DSR <-- Data Set Ready
7 Signal Ground Carrier Detect (used for modem control)
8 CD <-- Data Terminal Ready (used for modem control only)
20 DTR -->  

Note: The auxiliary port supports hardware flow control and modem control.

Console Cable Kit

A console cable kit is provided with your router. Use this kit when you connect your router to a PC or a terminal.

The console cable kit contains these items:

  • RJ-45-to-RJ-45 console cable (blue)

  • RJ-45-to-DB-25 adapter (gray)

  • RJ-45-to-DB-9 adapter (gray)

Note: The Cisco 7200 Series and Cisco 7301 are not shipped by default with a console cable kit. If a console cable is required, order an accessory kit (part number: ACS-2500ASYN).

RJ-45-to-RJ-45 console cable RJ-45-to-DB-25 adapter RJ-45-to-DB-9 adapter

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Cisco RJ-45 Component Guide

This chart summarizes the RJ-45 components of Cisco:

RJ-45 Component Guide

Style Catalog Part Number Catalog Description Label Shielded?
DTE CAB-500DTF= DB-25 CONNECTOR, DTE FEMALE 29-0810-01/29-DTF-01 no
DTE CAB-500DTM= DB-25 CONNECTOR, DTE MALE   no
modem CAB-25AS-MMOD= CABLE CONN-MODEM TO RJ45 SHLD   yes
modem CAB-MMOD= ADP,RJ45/DSUB 29-0881-01/29-MMOD-01 no
DCE CAB-500DCF= DB-25 CONNECTOR, (non modem) DCE FEMALE 29-0809-01/29-DCF-01 no
DCE CAB-500DCM= DB-25 CONNECTOR,(non modem) DCE MALE 29-0808-01/29-DCM-0129- 0808-01/29-DCM-01 no
NA Rolled Cable CABASY,RJ45 ROLLED, MODULAR 72-0876-01/CAB-500RJ NA
NA Straight Cable –not in catalog– 31-0756-01 NA
Cable for DB-25/DB-9 Connection
NA Depends on the router* RJ-45 to DB-9 female an all in one cable 72-3383-01 NA
NA CAB-R23= RS 232 Straight-through Cable NA
NA Depends on the router* DB-9 Male to DB-25 male for Modem connection 29-4043-01 NA

The first seven entries are DB-25 connectors, and the last two are RJ-45 cables. Connectors are described in terms of their sex and their role. For example, an FDTE is a female DTE style connector, an MMOD is a male modem style connector, and so on. Remember, you need shielded cables in order to run at 115.2 kbps.

Related Information

Updated: Sep 03, 2006
Document ID: 12223