This object specifies whether this peer is the
preferred one over the others.
It's value is encoded as follows:
0 - unknown
1 - not preferred
2 - preferred
When the value of this object is 'not preferred',
NTP chooses the peer with which to synchronize the
time on the local system. If this object is set to
'preferred', NTP will choose the corresponding peer to
synchronize the time with.