The choice between leaving the protocol of a bridge in MikroTik configured as “none” or changing it to “RSTP” (Rapid Spanning Tree Protocol) depends on the specific needs of your network and the objectives you are looking to achieve in terms of performance, scalability and reliability.

Protocol None

• Use: This configuration is basically not using any Spanning Tree protocol on the bridge. It is useful in scenarios where you are sure that there will be no loops in the network, either because of a simple network design or because you are strictly controlling the topology.
• Advantages: Less overhead in processing and latency, since there are no STP/RSTP algorithm calculations on the switches.
• Disadvantages: If a loop is accidentally formed in the network due to a configuration error or connecting a cable in the wrong place, it can cause broadcast storms that could crash the network.

RSTP (Rapid Spanning Tree Protocol)

• Use: RSTP is an evolution of Spanning Tree Protocol (STP) designed to provide faster network convergence. It is useful in more complex networks where there is a risk of loops or when dynamic changes in the network topology are expected.
• Advantages: Provides protection against network loops by detecting and disabling links that could cause them. RSTP can quickly adapt to changes in network topology, disabling or enabling links as necessary to keep the network operational without loops.
• Disadvantages: Uses more system resources and may introduce a small latency due to the algorithm's calculation to keep the spanning tree loop-free.

When to Use Each

• none: If your network is small, static (with few or no topology changes expected) and you can guarantee that there will be no network loops, setting the bridge protocol to “none” may be sufficient and more efficient.
• RSTP: In more complex, dynamic networks, or if you simply want the peace of mind of having loop protection, it is advisable to use RSTP. It is especially useful in environments where network changes are frequent or where devices are connected and disconnected regularly.

The decision between “none” and “RSTP” should be based on a careful evaluation of your network and your specific performance and security priorities.

In general, if there is any possibility of network loops or if the network is complex and dynamic, RSTP is the recommended option to avoid potential problems and ensure network stability.