title: rcache type freeradius rlm_krb5
body: <p>I am currently experiencing the problem that my freeradius installation with the kerberos5 module does not like my rcache. It spits this error when authenticating.</p>
  <pre><code>ERROR: (0) krb5: Error verifying credentials (-1765328174): Generic preauthentication failure
  </code></pre>
  <p>According to <a href="https://support.kemptechnologies.com/hc/en-us/articles/203860275-Kerberos-Constrained-Delegation" rel="nofollow noreferrer">Kemptechnologies</a> this error code means the rcache format is not supported.</p>
  <pre><code>-1765328174
  KRB5_RCACHE_BADVNO
  Unsupported replay cache format version number
  </code></pre>
  <p>I tried to disable rcache by using the information provided by MIT.</p>
  <p><a href="http://web.mit.edu/kerberos/krb5-devel/doc/basic/rcache_def.html" rel="nofollow noreferrer">http://web.mit.edu/kerberos/krb5-devel/doc/basic/rcache_def.html</a></p>
  <p>Setting KRB5RCACHETYPE to none to disable it, setting it to <code>dfl</code> and setting the KRB5RCACHEDIR to <code>/tmp</code> but freeradius seems to not like any option.</p>
  <p>Can anyone tell me how i have to format the rcache so that freeradius is able to read it?</p>