title: Assign IPs to programs/processes
body: <p>I need to assign different IP addresses to different processes (mostly PHP &amp; Ruby programs) running on my Linux server. They will be making queries to various servers, including the situation where processes connecting to the same external server should have different IPs.</p>
  
  <p>How this can be achieved?</p>
  
  <p>Any option (system wide, or PHP/Ruby-specific, using proxy servers etc) will suit me.</p>