RE: Reverse telnet on Catalyst c3560, c3550, c2950 possible?

From: Daniel Kutchin (daniel@kutchin.com)
Date: Thu Feb 01 2007 - 09:26:11 ART


Dan,

Thanks.

That was a typo from me. It was a con port not an aux port.
Since I only have console ports on switches available, it looks like I can't
do reverse telnet with them. Or can I?

Daniel

From: Dan C [mailto:cdan2154@gmail.com]
Sent: Donnerstag, 1. Februar 2007 12:50
To: Daniel Kutchin
Subject: Re: Reverse telnet on Catalyst c3560, c3550, c2950 possible?

Hi Daniel,

Did you try to do a show line and clear line 1 confirm and telnet again ? In
my setup I use an access server using asynch ports and works fine with all
switches, my line configs on the Access Server:

line vty 16 29
 exec-timeout 0 0
 privilege level 15
 logging synchronous level all
 no login
 transport input telnet

and for the ports:

ip host sw2 2011 201.201.1.1
ip host r4 2005 201.201.1.1
ip host r6 2010 201.201.1.1
.............................................
.........................................
interface Loopback0
 ip address 201.201.1.1 255.255.255.0
 no ip directed-broadcast

I am not sure if you can connect via console ports using just a console
cable, also it looks like you are trying to configure the line aux 0 instead
of line con 0....

Cheers, Dan

On 2/1/07, Daniel Kutchin <daniel@kutchin.com> wrote:
Folks,

I can't configure reverse telnet on my catalyst switches to use their
console ports as a terminal server.

Did I miss something, or this is not an available feature on Catalyst c3560,
c3550, c2950 switches?

Here is the well known procedure (at least on Cisco routers):

Say, you want to access switch sw2 (it could be a router as well) via
reverse telnet from sw1.

Join the console ports with a flat Cisco (roll-over) cable .

sw1 |CON|-----|CON| sw2

Don't need to do anything else on sw2 (except to set line-login and enable
passwords)

sw1(config)#line con 0

sw1(config-line)# no exec

sw1(config-line)# transport input all

sw1(config-line)# transport output all

sw1(config-line)# stopbits 1

sw1(config-line)# exit

sw1(config)#

sw1(config)#

sw1(config)# int loopback0

sw1(config-if)# ip add 1.1.1.1 255.255.255.255

sw1(config-if)# end

sw1#

sw1#

sw1# show line con 0

   Tty Line Typ Tx/Rx A Modem Roty AccO

     0 CTY 9600/9600 - - - -

sw1#

sw1# !-----*----line 0,

sw1# !- then reverse-telnet on sw1-loobpack0 int, port 2000 +0,

sw1# !- to access sw2

sw1#

sw1#telnet 1.1.1.1 2000

sw1# Trying 1.1.1.1, 2000 ...

% Connection refused by remote host

Just for curiosity, I have tried telnet port 2001 and physical interfaces as

well - to no avail.

sw1#telnet 1.1.1.1 2001

Trying 1.1.1.1, 2001 ...

% Connection refused by remote host

sw1#telnet 192.168.0.18 2000

Trying 192.168.0.18, 2000 ...

% Connection refused by remote host

sw1#telnet 192.168.0.18 2001

Trying 192.168.0.18, 2001 ...

% Connection refused by remote host

---

Daniel Kutchin



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