#!rsc by RouterOS
# RouterOS script: rotate-ntp
# Copyright (c) 2013-2021 Christian Hesse <mail@eworm.de>
# https://git.eworm.de/cgit/routeros-scripts/about/COPYING.md
#
# rotate the ntp servers
# https://git.eworm.de/cgit/routeros-scripts/about/doc/rotate-ntp.md

:local 0 "rotate-ntp";
:global GlobalFunctionsReady;
:while ($GlobalFunctionsReady != true) do={ :delay 500ms; }

:global NtpPool;

:global LogPrintExit2;

:local Ntp1;
:local Ntp2;

:if ([ / system ntp client get enabled ] != true) do={
  $LogPrintExit2 warning $0 ("NTP client is not enabled!") true;
}

:do {
  :set Ntp1 [ :resolve ("0." . $NtpPool) ];
  :set Ntp2 [ :resolve ("1." . $NtpPool) ];
} on-error={
  $LogPrintExit2 warning $0 ("Resolving NTP server failed.") true;
}

$LogPrintExit2 info $0 ("Updating NTP servers to " . $Ntp1 . " and " . $Ntp2) false;
/ system ntp client set primary-ntp=$Ntp1 secondary-ntp=$Ntp2;