Change /etc/network/interfaces subnet

interface_change

#!/usr/bin/env ruby

# Purpose
# Iterate over a range of IP addresses
# Change the /etc/network/interfaces subnet

# WARNING!
# I haven't tested this yet
# It might not work

require 'rubygems'
require 'net/ssh'

hosts = (2..254).map {|x| "172.16.31.#{x}"}                                                                                                                                                                                                                               
username = "your_username_here"
password = "your_password_here"
cmd = "sed -i -r -e '/netmask/ s/255.255.255.0/255.255.254.0/' /etc/network/interfaces && echo $?"

hosts.each do |host|
  begin
    Net::SSH.start( host , username, :password => password, :timeout => 5) do |ssh|
      results = ssh.exec! cmd
      if results = 0
          puts "everything went well!"
      else
          puts "error status #{results}"
      end
    end 
  rescue Timeout::Error  
    puts "  Timed out"  
    puts host
  rescue Errno::EHOSTUNREACH  
    puts "  Host unreachable"  
    puts host
  rescue Errno::ECONNREFUSED  
    puts "  Connection refused"  
    puts host
  rescue Net::SSH::AuthenticationFailed  
    puts "  Authentication failure"  
    puts host
  end  
end