Physical Set Up

  1. Use a standard Cisco console cable or create a cable with the following DB9 to RJ-45 connections.

  2. Connect the rollover UTP cable to the router A AUX port and DB9 connector to the router B's console port.

  3. Proceed to the router configuration in the next section.


RJ-45 Adapter Pinouts to DB9 DCE (non-modem)

From Cisco A AUX port to Router B (or other standard DB9 console port) using straight UTP cable


AUX Port
RJ45 Pinouts

Color

Assignments

DCE Style (non-modem) DB9 Pinouts

Assignments

1

Blue

RTS(out)

8

CTS (Clear To Send)

2

Orange

DTR(out)

6

DSR (Data Send Ready)

3

Black

TX+(out)

2

RXD

4

Red

TX-

5

GND

5

Green

RX-

5

GND

6

Yellow

RX+(in)

3

TXD

7

Brown

DSR(in)

4

DTR (Data Terminal Ready)

8

White/Grey

CTS

7

RTS (Ready-To-Send)


Router Configuration

1. Determine the line number for the AUX port on your router.

For example:

# sh line

Tty Line Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns Int
0 0 CTY - - - - - 0 0 0/0 -
1 1 AUX 9600/9600 - inout - - - 0 0 0/0 -
* 194 194 VTY - - - - - 3 0 0/0 -
195 195 VTY - - - - - 0 0 0/0 -
196 196 VTY - - - - - 0 0 0/0 -
197 197 VTY - - - - - 0 0 0/0 -
198 198 VTY - - - - - 0 0 0/0 -


2. Define a loopback for reverse Telnet and IP host using TTY number from Step 1.


ip host rtsh1 2001 10.10.10.1

!

interface Loopback0

ip address 10.10.10.1 255.255.255.255


3. Setup aux 0 for reverse telnet.


line aux 0
modem InOut
no exec
transport input all
transport output all
stopbits 1


4. Telnet to the router loopback interface and port. (2000 + Aux line number)


For example: telnet 10.10.10.1 2001

Referance:

https://splash.riverbed.com/thread/3128

https://supportforums.cisco.com/thread/46652