Cisco 800 Auxiliary port Particularity (Hardware)

[deternay2010]

Hi Everybody,

Cisco 800 routers series have a hardware particularity for the auxiliary port witch is in the same physical interface as the console port.

my issue is to use the aux port to setup reverse telnet in a cisco 881G, running the IOS version 12.4(22)T1 (fc5).

sh run Output:

=======

line con 0
exec-timeout 0 0
modem enable
no exec
transport preferred none
transport output all
stopbits 1
flowcontrol hardware
line aux 0
exec-timeout 5 0
password cisco1
login
modem InOut
modem autoconfigure discovery
no exec
transport input all

transport output all
stopbits 1
flowcontrol software

=============

a loopback interface has been configured and is up.

The problem is when i telnet the loopback addresse, port 2001 (where 1 is the aux tty number) i get :

Router#sw
Trying SW (93.18.49.192, 2001)... Open

User Access Verification

Password:
Password OK

and after noting !!! (the cursor in the bottom).

Many thanks in advance for your help.

Regards,

[netascom-uy]

Hi,

the problem is that the AUX port had a initial bad configuration.

You need to set the next parameters:

line aux 0

     speed 9600

     stopbits 2

     databits 8

     transport input all

     terminal-type xterm

And now it's ready.

good Luck

[richardbergen]

according to Cisco doumentation you need to enter the following command:

line con 0

modem enable

This is because the AUX and Console port are the same physical interface and one can only be active at a time. You have to effectively disable the console port by entering "modem enable" by which then enables the AUX port (for modem or reverse telnet).

This can be seen in the manual on page 5-13, Step 15 on : http://www.cisco.com/en/US/docs/routers/access/800/860-880-890/software/configuration/guide/SCG880-860.pdf