title: Kerberos fails when accessing site by IP address
body: <p>Problems appear when accessing Kerberos protected site by IP address.
  For example:</p>
  
  <p><code>http:/10.10.1.x:3001/</code> gives failure.</p>
  
  <p><code>http:/my-host:3001/</code> sso is completes successfully.</p>
  
  <p>Apache error logs say:</p>
  
  <blockquote>
    <p>src/mod_auth_kerb.c(1261): [client 10.10.1.x] Acquiring creds for
    HTTP@10.10.1.x [client 10.10.1.x] gss_acquire_cred() failed:
    Unspecified GSS failure.  Minor code may provide more information (Key
    table entry not found)</p>
    
    <p>src/mod_auth_kerb.c(1261): [client 10.10.1.x Acquiring creds for
    HTTP@my-host [debug] src/mod_auth_kerb.c(1407): [client 10.10.1.x]
    Verifying client data using KRB5 GSS-API [debug]
    src/mod_auth_kerb.c(1423): [client 10.10.1.x] Verification returned
    code 0</p>
  </blockquote>
  
  <p>As you could see Kerberos tries to find <code>HTTP@10.10.1.x</code> or <code>HTTP@my-host</code> principals. For both principals created dummy accounts in ActiveDirectory. In keytab file also included both of them:</p>
  
  <pre><code>KVNO Timestamp         Principal
  ---- ----------------- -----------------------------------------------------
     5 01/01/70 03:00:00 HTTP/10.10.1.x@MY_DOMAIN.LAN (ArcFour with HMAC/md5)
  
    11 09/04/12 12:03:01 HTTP/my-host@MY_DOMAIN.LAN (ArcFour with HMAC/md5)
  </code></pre>
  
  <p>Kinit works for both of them.</p>
  
  <p>Kerberos config on server:</p>
  
  <pre><code>   Krb5Keytab /etc/krb5.keytab
     AuthType Kerberos
     KrbMethodNegotiate On
     AuthName "Kerberos Login"
     KrbAuthRealms MY_DOMAIN.LAN
     KrbVerifyKDC Off
     KrbMethodK5Passwd On
     Require valid-user
  </code></pre>
  
  <p>Someone could guess where the problem is? Is it possible to use IP address in Kerberos SSO?</p>