How to determine if my lymph node is hard?

Function/condition: The lymphatic system absorbs and carries things too big to go into the arteries and veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph to see if anything bad is there like bacteria, viruses, cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge/hard in response to the inflammation created when they react.