To enable and configure SSH on Juniper SRX for remote management

To enable and configure SSH on a Juniper SRX device for remote management, follow these steps:

Step 1: Ensure the Interface Has an IP Address

Before enabling SSH, make sure the SRX device has an IP address configured on an interface. SSH requires an IP address on the device to communicate with remote clients.

Example for configuring an IP address on an interface:

set interfaces ge-0/0/0 unit 0 family inet address 192.168.1.1/24

This example configures the ge-0/0/0 interface with an IP address of 192.168.1.1/24.

Step 2: Configure the Management Access

Ensure that the management interface (such as fxp0 or the interface that connects to your network) is configured with an IP address if it hasn't been already.

Example for fxp0 (management interface) configuration:

set interfaces fxp0 unit 0 family inet address 192.168.100.1/24

This configures the fxp0 interface with an IP address of 192.168.100.1/24.

Step 3: Enable SSH

To enable SSH for remote management, use the following commands:

1. Enable the SSH service:

   set system services ssh
   

2. (Optional) Set the SSH version to 2 (recommended for security):

   set system services ssh protocol-version v2
   

   By default, Junos uses SSH version 2, but this ensures that it is explicitly configured.

Step 4: Configure a Username and Password for Authentication

To enable SSH access, you'll need to configure a user account with login credentials. This user account will be used for authentication when accessing the SRX device via SSH.

1. Create a user (e.g., admin):

   set system login user admin class super-user authentication plain-text-password
   

2. Set the password for the admin user (you will be prompted to enter a password):

   set system login user admin authentication plain-text-password
   

   Enter a strong password when prompted.

Step 5: Configure SSH Access Control (Optional)

You can specify which interfaces or IP addresses are allowed to access the SRX device via SSH. This is an optional security step but is highly recommended.

1. Allow SSH access from a specific network or interface: For example, if you want to allow SSH access from the 192.168.100.0/24 subnet:

   set system services ssh root-login deny
   set system services ssh allow-remote-commands
   set system services ssh allow-hosts 192.168.100.0/24
   

   This configuration allows SSH access from the 192.168.100.0/24 subnet but denies root login (which is a good security practice).

Step 6: Commit the Changes

Once the configuration is complete, commit the changes to apply them:

commit

Step 7: Test SSH Access

To verify that SSH is enabled and functioning, try to SSH into the SRX device from a remote machine:

ssh admin@192.168.100.1

Replace admin with the username you configured and 192.168.100.1 with the actual IP address of the management interface.

Additional Configuration (Optional)

• SSH Key-Based Authentication: If you prefer key-based authentication over password-based authentication, you can configure SSH key pairs:
  • Generate SSH keys on your local machine and copy the public key to the SRX device:

    set system login user admin authentication ssh-rsa "ssh-rsa AAAAB3Nza...yourkeyhere...=="
    

• Configure Logging for SSH Sessions: You can also configure logging to monitor SSH access:

  set system syslog host 192.168.100.200 any any
  set system syslog file ssh-logs match "sshd"
  

  


After completing these steps, you should be able to access your SRX device via SSH for remote management. Make sure the appropriate firewall policies are in place to allow SSH traffic if necessary.