How does any switch get sold in the last 10 years which doesn’t implement at least a simplified spanning tree? We had to implement a distributed spanning tree algorithm for OMSCS CS6250, two assignment ago which was a few hundred lines of code. If a switch can see itself over a port, can’t it just disable both ports? This would prevent users causing issues, unproductivity and a nightmare of network troubleshooting.
That code should exist in the $69 desktop switch and up, no excuses not to add a few hundred lines of code.