The purpose of the Diffie Hellman key exchange is to agree on a shared secret without sending it on the wire. I have always believed that every DH-session is unique with random large primes. Is DH using the same numbers every time when conneting to the same peer/device/server?
The reason for my question is that I read that PFS (Perfect Forward Secrecy) is being used on top of DH to make sure that the key is unique for every session.