Ssh Server Config

  



Ssh Server Config

  1. Ssh Server Config File
  2. Sshd Configuration

The server configuration file is located at /etc/ssh/sshdconfig. The client configuration settings can be found in /etc/ssh/sshconfig (system wide) or /.ssh/config (per user). Settings can also be specified during the connection by providing a command-line option. And the config file 'sshdconfig'. The SSH server is configured to run as a service. At the moment of this writing, it doesn't start automatically. You need to configure it manually.

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 Server Config

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

Ssh Server Config File

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:

Server
  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.

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

Ssh Server Config
  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.

Sshd Configuration

OK, the ssh works perfectly.