configure PKINIT on Linux got No realms configured correctly for pkinit support

[Vivian zhang]

HI,
 
I am trying to get my Linux system to support PKINIT.  I followed the instruction on MIT website to generate keys and certificate, etc.  I have also installed plugin (Krb5-plugin-preauth-pkinit-1.10.2-3.16.1.i586).  
 
However, it didn't work.  There are so little information online to see what it's wrong.  Can anybody help?  The error I got from KDC log is:
 
(Error): preauth pkinit failed to initialize: No realms configured correctly for pkinit support
(info): setting up network...
(info): listening on fd 7: udp 0.0.0.0.88 (pktinfo)
..........
 
Anybody has encounter this problem or knows what's going wrong? 
 
Thanks
 
Vivian