Loop-free layer 2 network design

When designing a network using the three tier model, it is a good idea to attempt to confine each VLAN to as few access switches as possible. By taking this to the extreme, we can confine each VLAN to only one physical switch. This will completely eliminate the need to employ Spanning Tree Protocol (STP) and would thus avoid the inefficiencies that come with blocking ports.

For example, the following situation avoids Layer 2 loops completely since each VLAN is confined to a physical switch:

Links

https://networklessons.com/cisco/ccnp-switch/cisco-campus-network-design-basics