s ▁Bon j our ▁S leep ▁Pro xy ▁service ▁is ▁an ▁open ▁source ▁component ▁of ▁zero ▁configuration ▁networking , ▁designed ▁to ▁assist ▁in ▁reducing ▁power ▁consumption ▁of ▁network ed ▁electronic ▁devices . ▁ ▁A ▁device ▁acting ▁as ▁a ▁sleep ▁proxy ▁server ▁will ▁respond ▁to ▁Mult ic ast ▁DNS ▁queries ▁for ▁another , ▁compatible ▁device ▁which ▁has ▁gone ▁into ▁low ▁power ▁mode . ▁ ▁The ▁low - power - mode ▁device ▁remains ▁as leep ▁while ▁the ▁sleep ▁proxy ▁server ▁respond s ▁to ▁any ▁Mult ic ast ▁DNS ▁queries . ▁ ▁When ▁the ▁sleep ▁proxy ▁server ▁sees ▁a ▁query ▁which ▁requires ▁the ▁low - power - mode ▁device ▁to ▁w ake ▁up , ▁the ▁sleep ▁proxy ▁server ▁sends ▁a ▁special ▁w ake - up - pack et ▁(" mag ic ▁packet ") ▁ ▁to ▁the ▁low - power - mode ▁device . ▁ ▁Finally , ▁communication ▁parameters ▁are ▁updated ▁via ▁Mult ic ast ▁DNS ▁and ▁normal ▁communic ations ▁proceed . ▁ ▁Apple ▁Inc . ▁describes ▁the ▁service ▁as ▁Bon j our ▁S leep ▁Pro xy ▁in ▁their ▁support ▁documents . ▁ ▁The ▁service ▁supports ▁the ▁W ake ▁on ▁Dem and ▁feature , ▁first ▁offered ▁in ▁Mac ▁OS ▁X ▁Snow ▁Leop ard . ▁ ▁Details ▁ ▁Address ▁resolution ▁protocol ▁▁ ▁The ▁sleep ▁proxy ▁service ▁respond s ▁to ▁address ▁resolution ▁protocol ▁requests ▁on ▁beh alf ▁of ▁the ▁low - power - mode ▁device : ▁When ▁a ▁sleep ▁proxy ▁sees ▁an ▁IP v 4 ▁AR P ▁or ▁IP v 6 ▁N D ▁Request ▁for ▁one ▁of ▁the ▁sleep