Cannot access local console port by telnet (C1111-4P)

[k-baba]

C1111-4P has only one serial port (con 0)

I tried to use the port for accessing console of another router, but telnet is rejected.

#telnet 10.10.10.10 2000
Trying 10.10.10.10, 2000 ...
% Connection refused by remote host

10.10.10.10 is loopback of C1111-4P and config of con 0 is as below:

line con 0
logging synchronous
modem InOut
no exec
transport input all
transport output all
stopbits 1
flowcontrol hardware

IOS version is 17.6.1a (a bit old)

What will be the cause of this issue ,  config, IOS or hardware limitation ?

[M02@rt37]

Hello @k-baba 

If you are trying to access the router using Telnet, then you should be looking at the configuration of the VTY (Virtual Terminal) lines, not the console line.

The `line con 0` configuration is for the console port, and for Telnet/ssh access, you need to configure the VTY lines.

Here's an example of how you can configure Telnet access on the VTY lines:

line vty 0 4
login local
transport input telnet

- `line vty 0 4`: This specifies the VTY lines from 0 to 4.
- `login local`: Enables local username and password authentication.
- `transport input telnet`: Specifies that Telnet is allowed for remote connections.

After making this configuration, you should be able to use Telnet to connect to the router.

[k-baba]

Since I got offline C1111-4P for testing, I can modify config freely.

Solution by wither "login local", "transport input telnet", "ip port-map telnet port tcp 2000" did not work.

I attach current config of C1111-4P.

Does anyone know how I can see port number allocated to console port ?  Is it 2000 by default ?

Best Regards,

[balaji.bandi]

 how I can see port number allocated to console port ?

You mean to say Physical console port  ? Console port used for emergency ?

you can change Telnet and SSH port from default to any free port you like.

[MHM Cisco World]

Line vty 0 4

Password xxxx

Login 

Transport input all

Then try access via telnet.

MHM

[MHM Cisco World]

You can use rotary under vty to access using 2001 or more but I dont recommendations it except case you need to separate vty.

So use defualt telnet command without specifying l4 port.

MHM

[balaji.bandi]

Hope you are trying to connect to other router using IP - not terminal console ?

also check make sure the IP able to ping before you start doing telnet 

#telnet 10.10.10.10 2000
Trying 10.10.10.10, 2000 ...
% Connection refused by remote host

as i see that you are telnet using port 2000 (by default only 23)

have you configured on Router to listen on different port example :

(config)#ip port-map telnet port tcp 2000

Verify :

#sh ip port-map | include telnet

Other note you posted only Console configuraton, Hope you have VTY Lines configured.

Note : telnet is not secured - so move to SSH for secure to protect devices.

[DaviRocK!]

Hi, did you tried with username and password local,

and

line vty 0 4
privilege level 15
login local

??

******* If This Helps, Please Rate *******

[jisif92125]

I'm unable to directly access specific community resources, but I can provide general guidance on using communities for troubleshooting and assistance.

Here's a structured approach:

1. Identify the Relevant Community:

   • Determine the product, brand, or topic associated with the console port you're having trouble with.
   • Search for official forums, support communities, or user groups related to that product or topic.

2. Create an Account (if necessary):

   • Most communities require membership for posting and participation.
   • Register using a valid email address and create a profile.

3. Search for Existing Solutions:

   • Before creating a new thread, explore the community's knowledge base or use its search function to find existing discussions about similar issues.
   • You might find helpful solutions without having to post a question.

4. Start a New Thread (if needed):

   • If you can't find a solution, create a new thread describing your problem clearly and concisely.
   • Include the following information:
     • Brand and model of the device
     • Operating system or firmware version
     • Specific error messages
     • Steps you've already taken to troubleshoot

5. Engage with Community Members:

   • Monitor your thread for responses and engage in discussions with community members.
   • Provide additional information or clarifications when requested.
   • Be patient and respectful of other members' suggestions and expertise.

6. Follow Community Guidelines:

   • Adhere to the community's posting guidelines and etiquette.
   • Use appropriate language and avoid offensive content.
   • Respect other members and their opinions.

Additional Tips:

• Use clear and concise language: Make your issue easy to understand and avoid technical jargon unless necessary.
• Provide as much detail as possible: The more information you provide, the better equipped community members will be to assist you.
• Be patient: It may take some time for community members to respond to your query.
• Express gratitude: Thank community members who offer helpful advice or solutions.

I hope this guidance helps you effectively utilize community resources to resolve your console port issue! Raising Cane’s Menu price