Problems setting reverse telnet using HWIC-16A

kasper123 · ‎11-24-2009

Hi,
I have trouble setting up a cisco 2811 as a terminal server using HWIC16A card and an octal cable.

The problem is that for some lines it works, and for some it does not even though they are setup the same.
When I do show line this is the output:

Router3#show line
   Tty Line Typ     Tx/Rx    A Modem Roty AccO AccI Uses Noise Overruns Int
*     0    0 CTY              -    -      -    -    -     5      0    0/0      -
      1    1 AUX   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/0    2 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/1    3 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/2    4 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/3    5 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/4    6 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/5    7 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/6    8 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/7    9 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
* 0/0/8   10 TTY   9600/9600 -    -      -    -    -     1      3 84547/0      -
0/0/9   11 TTY   9600/9600 -    -      -    -    -     0     12 297130/0      -
*0/0/10   12 TTY   9600/9600 -    -      -    -    -     1      0    0/0      -
*0/0/11   13 TTY   9600/9600 -    -      -    -    -     2      1    0/0      -
0/0/12   14 TTY   9600/9600 -    -      -    -    -     1      0    0/0      -
0/0/13   15 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/14   16 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/0/15   17 TTY   9600/9600 -    -      -    -    -     0      0    0/0      -
0/1/0   18 TTY 115200/115200- DialIn    -    -    -     0      0    0/0      -
0/1/1   19 TTY 115200/115200- DialIn    -    -    -     0      0    0/0      -
   Tty Line Typ     Tx/Rx    A Modem Roty AccO AccI Uses Noise Overruns Int

    514 514 VTY              -    -      -    -   23     0      0    0/0      -
    515 515 VTY              -    -      -    -   23     0      0    0/0      -
    516 516 VTY              -    -      -    -   23     0      0    0/0      -
    517 517 VTY              -    -      -    -   23     0      0    0/0      -
    518 518 VTY              -    -      -    -   23     0      0    0/0      -
    519 519 VTY              -    -      -    -   23     0      0    0/0      -
    520 520 VTY              -    -      -    -   23     0      0    0/0      -
    521 521 VTY              -    -      -    -   23     0      0    0/0      -
    522 522 VTY              -    -      -    -   23     0      0    0/0      -
    523 523 VTY              -    -      -    -   23     0      0    0/0      -
    524 524 VTY              -    -      -    -   23     0      0    0/0      -
    525 525 VTY              -    -      -    -   23     0      0    0/0      -
    526 526 VTY              -    -      -    -   23     0      0    0/0      -
    527 527 VTY              -    -      -    -   23     0      0    0/0      -
    528 528 VTY              -    -      -    -   23     0      0    0/0      -
    529 529 VTY              -    -      -    -   23     0      0    0/0      -

Line(s) not in async mode -or- with no hardware support:
20-513
Router3#

As you can see there are some overruns on line 10 and 11 and I'm not sure wthat that means and what is causing it.

I'm able to connect to line 10 but when I connect to line 11 I get the message:

Router3#telnet 10.10.10.109 2012

Trying 10.10.10.109, 2012 ...

% Connection refused by remote host

This is how reverse telnet has been configured:

ip host Router1 2010 10.10.10.109

ip host Router2 2011 10.10.10.109

ip host Switch 2012 10.10.10.109

ip host ASA1 2013 10.10.10.109

ip host ASA2 2014 10.10.10.109

ip host ACE1 2015 10.10.10.109

ip host ACE2 2016 10.10.10.109

ip host MARS 2017 10.10.10.109

line con 0

login local

line aux 0

session-timeout 20

transport input all

line 0/0/0 0/0/14

session-timeout 20

transport input all

escape-character BREAK

telnet break-on-ip

telnet ip-on-break

line 0/0/15

line 0/1/0 0/1/1

password Password

login

modem Dialin

transport input all

stopbits 1

speed 115200

flowcontrol hardware

line vty 0 4

access-class 23 in

privilege level 15

login local

transport input telnet

Does anyone have an idea what is wrong?

Thank you.

Peter Paluch · ‎11-24-2009

Hello,

A couple of suggestions:

Make sure that all your ports on the HWIC-16A card use the proper flow control, and also make sure that the devices connected to the octal cable are using the same method of flow control as well.
On the configuration of the HWIC lines, use the no exec command. The reason is that if any message is sent from the attached devices to the HWIC card (such as logging message) while there is no session running on that port, the router with the HWIC card will start an EXEC session for that port, thereby disabling the option to reverse telnet to that port.

Best regards,

Peter

kasper123 · ‎11-26-2009

Hi Peter,

Thank you for taking the time to reply.

I have added the no-exec command on all the lines.

Regarding your first suggestion (the flow control): I don't have anything set on the lines.

I see that the options for flowcontrol are:

Router3(config-line)#flowcontrol ?
NONE Set no flow control
hardware Set hardware flow control
software Set software flow control

What do you suggest I set for flow controll on the lines?

Peter Paluch · ‎11-26-2009

Hello,

You are welcome. Regarding the flow control - while I am not completely sure I believe that the default is no flow control. I believe that for your needs, the software flow control is sufficient. So if possible, set the flow control both on your HWIC-16A and the devices connected to your terminal server to use the software flow control.

Best regards,

Peter