Authenticated NTP still indicating that is in syn when it is not

Solution Unverified - Updated -

Issue

  • Authenticated NTP is configured using pre shared symetric keys: https://access.redhat.com/site/solutions/393663.
  • It works as expected but if a man in the middle attack is simulated by changing the key on the upstream ntp device (Cisco), RHEL ntp client continues to indicate that it is syncing without problems.
  • There are no indications in syslog and ntpq -p still shows the asterix "*" next to the upstream device.
  • In ntpq -c as the condition field does switch from sys.peer to rejected:
ind assID status  conf reach auth condition  last_event cnt
===========================================================
  1  6620  e033   yes   yes   ok     reject  lost reach  3

Environment

  • Red Hat Enterprise Linux
  • Network Time Protocol (NTP)
  • Cisco as NTP server

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