Short and complete guide to configure SSH on Cisco router and switch for secure remote connection. The Secure Shell (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. The best-known example application is for remote login to computer systems by users.

SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server. Common applications include remote command-line login and remote command execution, but any network service can be secured with SSH. The protocol specification distinguishes between two major versions, referred to as SSH-1 and SSH-2.

The typical use of SSH Protocol

The protocol is used in corporate networks for:

• providing secure access for users and automated processes
• interactive and automated file transfers
• issuing remote commands
• managing network infrastructure and other mission-critical system components.

Configure SSH on Cisco Router or Switch

To configure SSH on Cisco router, you need to do:

1. Enable SSH on Cisco router.
2. Set Password for SSH.
3. Force remote access to use SSH.
4. Enable Password Encryption.
5. Add domain name Server (DNS).
6. Add Username and Password.

Let’s enable and configure SSH on Cisco router or switch using the below packet tracer lab. The configure on a packet tracer lab and real Cisco devices are the same. Just try to learn and do it what the SSH remote authentication needs.

Download the packet tracer lab or create your own lab. SSH Configuration Packet Tracer Lab.

In this example, I just enable and configure SSH on SW1 and trying to access it from PC1. It’s enough to learn how to configure SSH on Cisco router.

R1>
R1>enable 
R1#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#
R1(config)#ip domain-name Technig.com
R1(config)#crypto key generate rsa 
The name for the keys will be: R1.Technig.com
Choose the size of the key modulus in the range of 360 to 2048 for your
  General Purpose Keys. Choosing a key modulus greater than 512 may take
  a few minutes.

How many bits in the modulus [512]: 1024
% Generating 1024 bit RSA keys, keys will be non-exportable...[OK]

R1(config)#
*Mar 1 0:5:57.974:  %SSH-5-ENABLED: SSH 1.99 has been enabled 
R1(config)#
R1(config)#username Admin password Technig
R1(config)#line vty 0 4
R1(config-line)#login local 
R1(config-line)#transport input ssh 
R1(config-line)#exit
R1(config)#ip ssh version 2
R1(config)#ip ssh authentication-retries 3
R1(config)#
R1(config)#ip ssh time-out 120
R1(config)#exit
R1#

That’s all. Let’s check the process one by one.

1. I have set DNS domain name with “IP domain-name” command.
2. Then configure the router to use RSA key pair with modulus size of 1024 bites for remote service authentication with “crypto key generate rsa” command.
3. Add username “Admin” with Password of “Technig” for ssh authentication.
4. Enabled ssh with “line vty 0 4” command.
5. Configure ssh to use local username and password with “login local” command. Remember that you can set a username and password for ssh with “username Admin password Technig” command as well. But here we configure ssh to use local username and password.
6. Configure the router to accept only ssh connection with “transport input ssh” command.
7. Configure ssh to version 2 using “IP ssh version 2” and set the authentication times to 3 with “IP ssh authentication-retries 3” command.
8. Finally set the ssh timeout to 120 seconds with “IP ssh time-out 120” command.

Related Article: Install SSH on CentOS 8.x and Red Hat Linux

The final step is to test the connectivity of ssh from PC1 with “ssh -l Admin 192.168.1.1” command for command prompt.

C:\>ssh -l Admin 192.168.1.1
Open
Password: 


R1>en
R1>enable 
Password: 
R1#

OK, the ssh works perfectly.

The post How to Configure SSH on Cisco Router or Switch? appeared first on TECHNIG.

This is how to configure VLAN on Cisco Switch or Virtual LAN on Cisco Switches in your network. A VLAN is a switched network that is logically segmented by function, project team, or application, without regard to the physical locations of the users. VLANs have the same attributes as physical LANs, but you can group computers even if they are not physically located on the same LAN segment. Any switch port can belong to a VLAN, and unicast, broadcast, and multicast packets are forwarded and flooded only to end stations in the VLAN.

Each VLAN is considered a logical network, and packets destined for stations that do not belong to the VLAN must be forwarded through a router or bridge or layer 3 switches. Because a VLAN is considered a separate logical network.

Here we just configure VLAN on Cisco switch and not talking about VTP, STP, and other advanced Switching techniques. It is the basic VLAN configuration. Read more about VLAN on Cisco Packet Tracer CCNA Lab.

How to Configure VLAN on Cisco Switch?

Let’s start to configure VLAN on Cisco switch using Cisco Packet Tracer. You can download the VLAN Lab or create your lab within Cisco packet tracer or other network simulators.

1. Open the VLAN lab and create these three VLAN and named Marketing, Accounting, and Sales. So let’s create them with the following commands.

2. First, change the switch name with “hostname” command.

Switch>enable 
Switch#configure terminal 
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname SW2
SW2(config)#

3. Now create the VLANs using “VLAN” command.

SW2(config)#vlan 2
SW2(config-vlan)#name Marketing 
SW2(config-vlan)#vlan 3
SW2(config-vlan)#name Accounting 
SW2(config-vlan)#vlan 4
SW2(config-vlan)#name Sales
SW2(config-vlan)#

4. Just type the “do sh vlan” command from config mod to see whether VLANs are created or not.

You see the VLANs are created successfully.

5. Now try to add interfaces to each of these VLANs. All the Interfaces ports are within the default VLAN and not yet grouped to Marketing, Accounting, and Sales. So try to add an interface to a VLAN with the “Switchport” command.

SW2(config)#interface fastEthernet 0/5
SW2(config-if)#switchport mode access 
SW2(config-if)#switchport access vlan 2
SW2(config-if)#exit
SW2(config)#interface fastEthernet 0/6
SW2(config-if)#switchport mode access 
SW2(config-if)#switchport access vlan 2
SW2(config-if)#

I have added the [fastEthernet 0/5] and [fastEthernet 0/6] to VLAN 2 which is our Marketing VLAN. In this method, we add each interface one by one, but you can use “Interface range” command to add a group of ports to a VLAN.

SW2(config)#interface range fastEthernet 0/2-4
SW2(config-if-range)#switchport mode access 
SW2(config-if-range)#switchport access vlan 4

6. Finally type “do sh vlan” and see the result again.

Now you can set up VLAN on your network Switches. The next step is configuring Inter-VLAN Routing. I hope you find this article helpful and do comment us about the qualities and improvements of Technig articles.

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