Sounds like an amplification attack, you are just in a rotation with a ton of other random hosts generating the traffic which is probably why the packet rate is

Sounds like an amplification attack, you are just in a rotation with a ton of other random hosts generating the traffic which is probably why the packet rate is low. You could try doing some research on the forged IPs and see who they are associated with. Also try pinging them, my guess is they are down or returning insane latencies. Either way I wouldn't lose sleep, any server I've ever managed or owned always got weird little visits from the packet goblins from time to time, it is fun puzzling them out. Once is an accident, twice is a coincidence, three times is an enemy action.