iMac listed 8 times in net hawk app

When I go into device manager, my imac device is listed 8+ times under the 2.4 gz -- with same mac addrress, different ip address.  It is also listed under the 5gh once and that is the ip address i'm actually connected to.  Pausing one of the 2.4ghz ones pauses all of them.   Why is it listing it multiple times with different ip addresses (ones I assume I connected from at one point in time) and if these are inactive now is there a setting that only shows active? how does the list get cleaned up so it only shows connected/active devices and not old connections?