Getting the trigger Object

Hi guys, i was making a pong game but i am coming across a problem.
When my ball (sphere collider) collides with one of the side walls (Box collider - trigger object), i want to know which wall it collided with (i put that tag in both walls). The problems is, OnTriggerEnter() method only tracks the object that is not the trigger. How should i get the information on which wall my ball collided with? Any help would be greatly appreciated.

The problems is, OnTriggerEnter() method only tracks the object that is not the trigger

I don’t follow this. The method signature for OnTriggerEnter() is as follows:

void OnTriggerEnter(Collider other)

So, if you want to know something about the game object to which this script is attached, you access this.gameObject. If you want to know something about the other object with which it just triggered, you access other.gameObject.