Remote-access Guide

3 configure remote access to the switch using telnet

by Prof. Jimmy Schulist Published 2 years ago Updated 1 year ago
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Log in the the device > Go to enable mode > Go to configuration mode > Enable Telnet and set a password. Router0> enable Router0# conf terminal Enter configuration commands, one per line. End with CNTL/Z. Router0 (config)# line vty 0 4 Router0 (config-line)# transport input telnet Router0 (config-line)# password P@ssword123

Full Answer

How to configure Telnet on Cisco switches and routers?

You can configure telnet on all Cisco switches and routers with the following step by step guides. But it’s not the best way to the wide-area network. However, we just going to enable telnet and ssh to test them for CCNA Certification exams. To enable telnet on Cisco router, simply do it with “ line vty ” command.

How to remotely access the CLI of a switch through telnet?

Enter the telnet command and then the IP address to access the CLI of the switch. Note: In this example, 192.168.100.105. Step 3. Enter the username and password of the switch in the User Name and Password fields accordingly. You should now have successfully remotely accessed the CLI of your switch through Telnet using the Terminal.

How to configure SSH to use telnet?

The configuration is the same as telnet, just the transport input ssh command change the line to Secure Shell. The configuration has completed, next, you must test ssh from a client PC. From a client PC, open the command line and type “ ssh -l Shais 192.168.10.1 ” then press enter.

How to remotely connect to router R1 using telnet?

Type telnet 192.168.10.1 and press enter, then enter the telnet password. Next type enable command and press enter, then type the router password. Now you are remotely connected to router R1 and you can execute all router commands through a telnet command-line interface.

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What is Telnet switch?

Telnet is a protocol used to connect to switches and other devices in your network. Telnet provides a connection from a computer to a remote switch. The connection allows access to make changes to the device without actually having to be on site.

Is Vty Telnet or SSH?

An efficient way to manage remote devices is to use VTY access, which is CLI-based remote access using Telnet or SSH. Telnet uses TCP port number 23. Telnet is a simple protocol and does not encrypt communications.

What do you need to configure on a switch to allow remote management?

To prepare a switch for remote management access, the switch must be configured with an IP address and a subnet mask. Keep in mind that to manage the switch from a remote network, the switch must be configured with a default gateway. This is very similar to configuring the IP address information on host devices.

What is Telnet configuration?

The Telnet protocol enables you to set up TCP/IP connections to a host. Telnet allows a person at one site to establish a TCP connection to a login server at another site and then passes the keystrokes from one device to the other. Telnet can accept either an IP address or a domain name as the remote device address.

What is Telnet and SSH?

Telnet (Telecommunications and Networks) and SSH (Secure SHell) are general-purpose client-server applications that allow users to interact with remote systems.

What is Vty in Telnet?

What Does Virtual Teletype (VTY) Mean? Virtual teletype (VTY) is a command line interface (CLI) created in a router and used to facilitate a connection to the daemon via Telnet, a network protocol used in local area networks. To connect to a VTY, users must present a valid password.

What are the steps to configure a switch?

How to configure a network switchStep 1: Connect to the console. ... Step 2: Set a management IP and default gateway. ... Step 3: Set hostname and domain name. ... Step 4: Set logins on VTY lines and console port. ... Step 5: Set Privileged EXEC password. ... Step 6: Enable SSH. ... Step 7: Create VLANs. ... Step 8: Add access ports to a VLAN.More items...•

Which protocol should be used to manage a switch remotely?

Secure Shell (SSH) is a protocol that provides a secure (encrypted) management connection to a remote device.

Why would you configure a switch with an IP address?

If you want to be able to manage your switch remotely over the network, your switch needs an IP address. If your switch has multiple VLANs configured, and you want to be able to manage the switch from each VLAN, the switch requires an IP address on a VLAN interface in each VLAN.

How do I connect to a remote computer using telnet?

To use telnet, follow the steps below:First, find out the ip address of the server/main computer. ... Select the Windows key and the R key.In the Run box type CMD.Select OK.Type Telnet 13531. ... If you see a blank cursor then the connection is fine.More items...•

How can I use telnet command?

AnswerOpen a command prompt.Type in "telnet " and press enter.For example, you would type “telnet 123.45. ... If a blank screen appears then the port is open, and the test is successful.If you receive a connecting... message or an error message then something is blocking that port.

Why do we use telnet?

Uses of Telnet Telnet can be used for a variety of activities on a server, including editing files, running various programs and checking email. Some servers enable remote connections using Telnet to access public data to play simple games or look up weather reports.

What is line Vty in Cisco?

The virtual terminal or “VTY” lines are virtual lines that allow connecting to the device using telnet or Secure Shell (SSH). Cisco devices can have up to 16 VTY lines. You can determine how many VTY lines you have by issuing “line vty 0 ?” from global configuration mode.

What is the meaning of line Vty 0 15?

Lines 0 15 is vty lines 0, 1, 2 ,3 ,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15. for example if you were type in global configuration mode, line vty 0 15 you will enter configuration for lines 0-15.

What is login local Vty?

login is used on vty and console and means that the password that is user for its authentication, is configured under vty and console as well. Login local, means that authentication uses locally configured credentials using the. username privilege <15> secret 0 password command in global configuration mode.

What is the difference between line Vty 0 4 and line Vty 5 15?

VTY lines are usually used for creating out-of-band management sessions to devices. If a password is not supplied on a vty line, that line cannot be used for managing the device. In some cases administrators may decide to let junior staff to use lines 0 - 4 and senior staff to use lines 5 - 15.

What is enable secret?

The command enable secret sets a privilege mode password and stores it in an encrypted format so that it isn’t visible when viewing the running configuration. If you already have a privilege mode password set ignore the command. Replace the word password with your strong password.

Can Cisco routers telnet?

Assuming you’ve configured the interface IP address settings properly just entering the following commands will configure your cisco router for telnet access.

Does Telnet store passwords?

Important:- As said earlier Telnet sends commands and passwords in plaintext over the network. The “enable secret” and “service password-encryption” commands only STORE the password in encrypted format

Where is telnet configuration?

Telnet configuration will be in the bottom of the configuration file. You can use show run command to see the configuration. You also can use filter commands to go telnet configuration directly run using show run | section vty.

What is telnet on Cisco router?

If you are not familiar with Telnet, then just remember; Telnet is a network protocol, that allows you to gain remote access to your devices. By the end of this article, you will be confident enough to configure and troubleshoot Telnet related issues on Cisco routers and switches. So, let’s get started. First of all, we will check our interface IPs ...

How to remotely access Cisco switch?

The Cisco Business Managed Switches can be remotely accessed and configured through the Command Line Interface (CLI). Accessing the CLI allows commands to be entered in a terminal-based window. If you prefer to configure using terminal commands on your switch through the CLI rather than the web-based utility, this would be an easier alternative. Certain tasks such as Layer 3 mode enabling can only be performed through the CLI.

How to remotely access CLI?

In order to remotely access the CLI of your switch, you must use an SSH or Telnet client. You must also enable the Telnet and SSH service on your switch first before you can access it remotely.

How to access CLI on switch?

This article provides instructions on how to access the CLI of your switch through SSH or Telnet using the following clients: 1 PuTTY - A standard Telnet and SSH client. You can download an installer here and install in your Windows computer. 2 Terminal - An application that is pre-installed in every Mac OS X computer. It is also known as the shell or the console.

How long does it take for SSH to disconnect?

The SSH sessions disconnect automatically after the idle time configured in the switch has passed. The default idle session timeout for SSH is 10 minutes.

What port number to use for SSH?

Step 3. Enter 22 as the port number to be used for the SSH session in the Port field.

Do you need to set IP address for SSH?

Important: Before you make an SSH or Telnet connection to the switch, you must set the IP address for the switch. For instructions, click here.

Why is my VTY connection refused?

You have not configured password (s) on the VTY lines, hence the connection is refused!

Can an IOS device authenticate with a local device?

Since much of the discussion in this thread has been about IDs and passwords lets have a little review and hope that some of the information may help lead to an understanding of the issue. An IOS device (switch or router) can authenticate with resources that are local to the device or it can authenticate using an authentication server (aaa etc). For this discussion we will focus on local authentication.

How to enable telnet on Cisco router?

To enable telnet on Cisco router, simply do it with “ line vty ” command. First of the first download the CCNA Lab to Enable Telnet and SSH on Cisco Router from Telnet and SSH Lab. The Lab is configured with DHCP server and all clients get an IP address from DHCP Server on Router.

What is telnet for Cisco?

The Telnet is an old and non-secure application protocol for remote control services. You can configure telnet on all Cisco switches and routers with the following step by step guides. But it’s not the best way to the wide-area network. However, we just going to enable telnet and ssh to test them for CCNA Certification exams.

What is SSH protocol?

Secure Shell or SSH is a secure protocol and the replacement for Telnet and other insecure remote shell protocols. So for secure communication between network devices, I strongly recommend using SSH instead of Telnet.

How to generate RSA keys?

Type “ crypto key generate rsa ” command and press enter when asking you “ How many bits in the modulus [512]: ” just type “ 1024″ and press enter. The system will generate 1024 bits keys to secure session lines. You can choose modules in the range of 360 to 2048.

Is telnet the same as ssh?

The configuration is the same as telnet, just the transport input ssh command change the line to Secure Shell. The configuration has completed, next, you must test ssh from a client PC.

Can you set your own password on telnet?

You can set your own password. The “ login ” command authenticate and ask you the password of telnet. If you type “ no login ” command , the telnet never authenticates for the password which is not a good practice in a real network environment.

Objective

The objective of this lab is to configure the switch for remote management such that the laptop PC residing on a remote network be used to login and manage it via ssh . To accomplish this, the following will be done:

Implementation

The following configuration commands will the required to configure a Cisco switch for remote management. The commands used here a for the lab represented in the network topology used here. However, the solution can be achieved in many different ways.

Verification

To verify that I have configured the Cisco switch for remote management via ssh, I try to access the switch using the laptop on the network 192.168.0.0/24 using ssh. Remember that both the laptop and the switch are on different networks. See the result below.

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