OK, I just found the problem.
It is my local host windows xp firewall, which blocked the communicate
between the host and guest.
disabled the windows's firewall, all goes well!
[user@workstation ~]$ ntpdate -d 192.168.17.1
2 Sep 21:02:18 ntpdate[1243]: ntpdate [log in to unmask] Fri Feb 22
03:55:28 UTC 2013 (1)
Looking for host 192.168.17.1 and service ntp
host found : 192.168.17.1
transmit(192.168.17.1)
receive(192.168.17.1)
transmit(192.168.17.1)