NTP time server problems

[liushu <liushu@mail.ihep.ac.cn>]

Hi :
   Now I want to set my IOC time synchronize with my Linux PC that means I 
make my PC the time server and the IOC the time client.But I'm failed.
   Firstly,I edited my /etc/ntpd.conf and added:server 192.168.20.155 (my ip 
address).Then I start ntp service by /usr/sbin/ntpd start but it shows me 
"ntpd time synchronization server failed".I run /usr/sbin/ntpdate and I 
got:"no servers can be used, exiting" the /usr/sbin/ntpq -p 
" remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 liushu          0.0.0.0         16 u    -   64    0    0.000    0.000 4000.00
 LOCAL(0)        LOCAL(0)        10 l   35   64    3    0.000    0.000 0.015"
  And I configed EPICS variables in st.cmd added(Are these variables defined 
in user's .bashrc file and not in every st.cmd file?):
    putenv("EPICS_TS_NTP_INET=192.168.20.155")  (my ip address)
    putenv("EPICS_TS_MIN_WEST=-420")  (China time zone)
  Then I reboot IOC.but it always told me "Failed to set time from Unix 
server"

  The contents of my ntpd.conf is below:
# Prohibit general access to this service.
#restrict default ignore
#restrict 66.187.224.4 mask 255.255.255.255 nomodify notrap noquery
                                                                                
# Permit all access over the loopback interface.  ......
#restrict 127.0.0.1                                                                                
                                                                                
# -- CLIENT NETWORK -------
# ......
restrict 192.168.0.0 mask 255.255.255.0 notrust nomodify notrap
                                                                                
# --- OUR TIMESERVERS -----
# ......
restrict 192.168.20.155 mask 255.255.255.255 nomodify notrap noquery
                                                                                
server 192.168.20.155
                                                                                
# --- NTP MULTICASTCLIENT ---
#......                                                                             
                                                                                
                                                                                
# --- GENERAL CONFIGURATION ---
#
# .......
                                                                                
server 127.127.1.0   #local time
fudge   127.127.1.0 stratum 10
                                                                                
#
# Drift file.  ......
#
driftfile /etc/ntp/drift
broadcastdelay  0.008
                                                                                
#
# ......
authenticate yes
#
# ......
keys            /etc/ntp/keys

     Thank you!

Best regards
liushu