You may not be suprised if MT decides to ban you for that
The minimum update interval, no scripting required, is 60 seconds:
https://wiki.mikrotik.com/wiki/Manual:I ... Properties
ddns-update-interval (time, minimum 60 seconds; Default: none) If set DDNS will attempt to connect IP Cloud servers at the set interval. If set to none it will continue to internally check IP address update and connect to IP Cloud servers as needed. Useful if IP address used is not on the router itself and thus, cannot be checked as a value internal to the router.
Note that this is specifically useful if MT is behind another router. If MT is the outside router, you don't need this setting as the router will update it's cloud address within 60 seconds automatically.
But, updating DNS is one. There are a few things needed for failover:
- the current connection needs to be disconnected/timed out (dpd)
- the client dns entry and intermediate cache entries need to be expired
- the connection has to be re-established
In my experience, in plain ipsec peers with dynamic addresses scenario, failover using ip cloud is simply not working. MT will keep connecting to the old address long after expiry for several minutes and even hours (Ticket#2019062422004454).
Therefore, if you need a quick failover solution, don't (ab)use ip cloud, but rather set up two tunnels and load balance or policy route between them.