title: Adding machineKey to web.config on web-farm sites
body: <p>We (our IT partner really) recently changed some DNS for a web farmed site we have, so that the two production server have round-robin DNS switching between them. Prior to this switch we didn't really have problems with <code>WebResource.axd</code> files. Since the switch, when we hit the live public URL, we get an error:</p>
  <blockquote>
  <p>CryptographicException</p>
  <p>Padding is invalid and cannot be removed.</p>
  </blockquote>
  <p>When we hit the specific servers themselves, they load fine. I've researched the issue and it seems since they're sharing assets between two servers, we need to have a consistent <code>machineKey</code> in the <code>web.config</code> for each server so they can encrypt and decrypt consistently between the two. My questions are:</p>
  <ol>
  <li>Can I generate a <code>machineKey</code> via a tool on the server, or do I need to write code to do this?</li>
  <li>Do I just need to add the <code>machineKey</code> to the <code>web.config</code> on each server or do you think I'll need to do anything else to make the two server work together? (Both <code>web.config</code>'s currently do not have a <code>machineKey</code>)</li>
  </ol>