[CentOS] ntpd stuck on stratum 16 = not synced

Maybe there's an ntp expert out there who can help me with this.  I have an NTP server serving our local network.  It is 
set up to use pool.ntp.org servers for it's upstream sync.  ntpq -p reveals that the server is stuck on stratum 16, 
which I understand means "not synced".  The clients are unable to sync with my local server because of this.  Here's the 
output of ntpq -p along with my ntp.conf file:

[root at ntpserver /root]# ntpq -p
      remote           refid      st t when poll reach   delay   offset    disp
==============================================================================
  echo.sureproxy. 0.0.0.0         16 u   29   64    0     0.00    0.000 16000.0
  nist.netservice 0.0.0.0         16 u   19   64    0     0.00    0.000 16000.0
  ntp.your.org    0.0.0.0         16 u   19   64    0     0.00    0.000 16000.0
  ntp.pbx.org     0.0.0.0         16 u   19   64    0     0.00    0.000 16000.0

# NTP cluster configuration file

server 0.rhel.pool.ntp.org
server 1.rhel.pool.ntp.org
server 2.rhel.pool.ntp.org
server 3.rhel.pool.ntp.org

#
# Drift file.  Put this in a directory which the daemon can write to.
# No symbolic links allowed, either, since the daemon updates the file
# by creating a temporary in the same directory and then rename()'ing
# it to the file.
#
driftfile /etc/ntp/drift
#multicastclient                        # listen on default 224.0.1.1
broadcastdelay  0.008

#
# Authentication delay.  If you use, or plan to use someday, the
# authentication facility you should make the programs in the auth_stuff
# directory and figure out what this number should be on your machine.
#
authenticate no

# by default, don't trusst and not allow modifications
restrict default notrust nomodify

# These machines are trusted for time, but no modifications allowed
restrict 10.1.0.0       mask 255.255.0.0 nomodify
restrict 10.100.0.0     mask 255.255.0.0 nomodify

# The local host is unrestricted
restrict 127.0.0.1

#
# Keys file.  If you want to diddle your server at run time, make a
# keys file (mode 600 for sure) and define the key number to be
# used for making requests.
#
keys            /etc/ntp/keys
trustedkey      65535
requestkey      65535
controlkey      65535

enable monitor