spacepc.de | Automate Switch Configurations with PowerShell & Plink

In network management, regularly retrieving and saving switch configurations is a key task that is often neglected 😉
This PowerShell script automates the process using Plink. With minimal adjustments, you can fetch the configuration from multiple switches simultaneously and save each in a text file. The text document is always named after the switch's IP address.

Prerequisites

Before using the script, ensure that:

plink.exe is available (e.g., from the PuTTY tools)
SSH is enabled on the switches
A text file with the switch IP addresses exists (one IP per line)
Valid SSH credentials are available

Script Overview

The following script reads IP addresses from a text file, establishes an SSH connection to each switch, executes a command to display the running configuration, and saves the results in a separate file for each IP address.

# Path to plink.exe and switche.txt
$plinkPath = ".\plink.exe"           # Path to the plink.exe executable used for SSH connections
$switchListPath = ".\switche.txt"    # Path to the text file containing the list of switch IP addresses

# SSH credentials
$username = "SSH-USER"          # Username for SSH login
$password = "SSH-PASSWORT"      # Password for SSH login

# Convert password to SecureString
$securePassword = ConvertTo-SecureString $password -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential ($username, $securePassword)

# Read IP addresses from switche.txt
$switchIPs = Get-Content $switchListPath

foreach ($ip in $switchIPs) {
    # Command to fetch the configuration
    $command = "show running-config"

    # Filename based on IP address
    $outputFileName = "$ip.txt"

    # Plink command to establish SSH connection and retrieve the configuration
    $plinkCommand = "& $plinkPath -ssh $username@$ip -pw $password -batch $command"

    # Execute the plink command and save the output
    Invoke-Expression $plinkCommand | Out-File -FilePath $outputFileName -Encoding utf8

    Write-Host "Configuration from $ip saved to $outputFileName"
}

Detailed Explanation

Path Assignment

The script starts by defining paths to Plink and the file with the switch IP addresses:

$plinkPath = ".\plink.exe"
$switchListPath = ".\switche.txt"

Make sure these paths are correct or adjust them to your environment.

Credentials

SSH login credentials are defined in plain text and then converted into a SecureString:

$username = "SSH-USER"
$password = "SSH-PASSWORT"
$securePassword = ConvertTo-SecureString $password -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential ($username, $securePassword)

Each IP address is then used in a loop to establish the SSH connection.

Retrieval and Storage of Configuration

For each IP address, a Plink command is generated and executed to retrieve the running configuration of the switch. The output is saved to a file named after the IP address.

foreach ($ip in $switchIPs) {
    $command = "show running-config"
    $outputFileName = "$ip.txt"
    $plinkCommand = "& $plinkPath -ssh $username@$ip -pw $password -batch $command"
    Invoke-Expression $plinkCommand | Out-File -FilePath $outputFileName -Encoding utf8
    Write-Host "Configuration from $ip saved to $outputFileName"
}

Adjustments for Other Switches

The command executed on the switch can be easily modified. Simply change:

$command = "show running-config"

to, for example:

$command = "show version"

to retrieve the software version of the switches instead.

Conclusion

This script allows efficient automated backup and archiving of switch configurations. By simply adjusting the command to be executed, it can be flexibly adapted to different requirements. Automation saves time and reduces the risk of manual errors during configuration backup.

Automated Retrieval and Storage of Switch Configurations Using PowerShell and Plink