Information
NTP is a protocol for synchronizing the clocks of computer systems over the network. On BIG-IP systems, accurate time stamps are essential to guarantee the correct behavior of a number of features.
While in most cases it is sufficient to configure a couple of time servers that the BIG-IP system will use to update its system time, it is also possible to define more advanced NTP configurations on the BIG-IP system.
Solution
Secure NTPD to work only as a client using ntp.conf