Reverse Telnet from 2610

May 19, 2006 4 Replies

Hi guys Having problems using reverse telnet.



Using the AUX port on a 2610 connecting to the Console port of a 3550 switch using a straight through cable.



AUX port on 2610 is configured like this: line aux 0 modem InOut transport input all stopbits 1 speed 19200 flowcontrol hardware



Loopback 0



10.0.0.1 255.255.255.0

The AUX port is on line 65 so therefore telnet 10.0.0.1 4065



I get the prompt for username and password.



The first problem was that each character I typed I got twice so I used the /noecho switch on the telnet command which resolved this.



The next problem is that I enter the username and password, but I then get nothing. It locks up and accepts no further input. I have to disconnected and start again but the same thing happens everytime.



Any help appreciated. Cheers Mike



Thanks but it makes no difference Cheers Mike

Mike, A few things.

  1. You should use 2065 rather than 4065 - All the Cisco documentation references reverse telnet via port 2000+n (n being the port number of the line). Even though this may not help right now, this might be a good standard practice.
  2. Have you tried using a roll-over (console) cable or a crossover in place of the straight through?
  3. I notied the AUX port is set to speed 19200 on the 2610, have you configured the same speed on the 3550? Console ports are usually only
9600 - might be a speed mismatch.
  1. What does the c>Hi guys

Reverse telnet to AUX (conected to PC running Hyperterm). This is of no use that I can think of except as a test:-)

My notes say: This works: Can type both ways. Telnet to Hyperterm.

line aux 0 no exec transport preferred none transport input telnet

3725 to PC with blue rollover cable.

telnet x.x.x.x 2097

R1#sh line Tty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns Int

  • 0 CTY - - - - - 2 0 0/0 - 97 AUX 9600/9600 - - - - - 2 0 0/0 -

Add to Aux0 "login local" (with no aaa new-model, and with user names) and we have login security.

I used a rollover cable (blue:) here. So since PC-console works with rolled cable and PC-aux works with rolled cable

aux and con must have the same pinout Therefore a rolled cable will be needed with aux-con.

The console port may not do handshaking. BTW an ethernet crossover is NOT useful here.

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