How do we stop layer 2 loops without stp?

Hi, 

STP is a simple protocol, which is used to prevent Layer-2 loops. But now a days we have many other technologies to prevent L2 loop like Cisco Fabric path, Etherchannel , shortest path bridging and many others that work to decrease dependance on STP. 

STP is used to prevent L2-loop as well as provide redundancy in any case of link failure. Otherwise it can be performed manually that is simply a admin headache.

Hope it helps.