add doc/rotate-ntp.md

doc/rotate-ntp.md

@@ -0,0 +1,40 @@
+Rotate NTP servers
+==================
+
+[◀ Go back to main README](../README.md)
+
+Description
+-----------
+
+RouterOS requires NTP servers to be configured by IP address. Servers from a
+pool may appear and disappear, leaving broken NTP configuration.
+
+This script allows to rotate IP addresses from a given pool.
+
+Requirements and installation
+-----------------------------
+
+Just install the script:
+
+    $ScriptInstallUpdate rotate-ntp;
+
+Configuration
+-------------
+
+The configuration goes to `global-config-overlay`, this is the parameter:
+
+* `NtpPool`: dns name of ntp server pool
+
+Usage and invocation
+--------------------
+
+Just run the script to update the NTP configuration with actual IP
+addresses from pool if required.
+
+Alternatively a scheduler can be created:
+
+    / system scheduler add interval=5d name=rotate-ntp on-event="/ system script run rotate-ntp;" start-time=startup;
+
+---
+[◀ Go back to main README](../README.md)  
+[▲ Go back to top](#top)

rotate-ntp

@@ -3,6 +3,7 @@
 # Copyright (c) 2013-2020 Christian Hesse <mail@eworm.de>
 #
 # rotate the ntp servers
+# https://git.eworm.de/cgit/routeros-scripts/about/doc/rotate-ntp.md
 
 :global NtpPool;