In MikroTik RouterOS, when you configure an “IP pool” (a set of IP addresses that can be dynamically assigned to devices on the network), you have the option to specify a “next pool”.

This option allows multiple IP address pools to be chained together, providing a way to manage and assign IP addresses in an efficient and scalable manner.

“Next Pool” functionality

The “next pool” field is used to specify another pool of IP addresses that the system should use once the current pool has been exhausted. That is, if all IPs in the current pool are in use and a new device requests an IP address, RouterOS will automatically start assigning addresses from the pool specified in “next pool”.

Leave the “Next Pool” at “None”

Leaving the “next pool” field at “none” means that there is no secondary pool specified to continue IP address assignments once the primary pool is exhausted.

In this case, if the pool runs out of available addresses, no more IP addresses can be assigned until one of the assigned addresses is freed or a new pool is added manually.

Implications of Setting “Next Pool” to “None”

1. Limited IP Management: Not having a “next pool” can limit the network's ability to expand or handle more devices than initially planned without manual intervention to add more addresses or pools.
2. Disruption Potential: In environments where demand for IP addresses can suddenly increase, not having a next pool configured could lead to situations where new devices cannot connect to the network until a reconfiguration is performed.
3. Ease: On the other hand, for small networks or for scenarios where the number of devices is predictable and stable, leaving the “next pool” at “none” can simplify configuration and management without negative repercussions.

Conclusion

Properly configuring IP pools and the “next pool” option in MikroTik is crucial to ensure efficient management of IP addresses on the network.

Leaving “next pool” at “none” is appropriate in situations where demand for IP addresses is stable and predictable, but it is advisable to plan carefully to avoid potential connectivity problems in growth or change scenarios.