128 and output circuit 124 transmits physical layer signals representing the data to network 106 when entering sleep mode pc 104 places network device 102 in magic packet mode step 204 for example pc 104 asserts a magic packet mode signal which can be conveyed to phy 108 in any number of ways for example a management interface such as management data input output mdio can be used to set a bit in memory 118 which can be monitored by phy power control circuit 120 as another example a dedicated pin of an integrated circuit comprising phy 108 can be used in response to the magic packet mode signal phy power control circuit 120 powers off serial data interface 114 of phy 108 step 206 in some embodiments mac power control circuit 130 powers off serial data interface 138 of mac 110 and can power off mac core 136 in response to the magic packet mode signal while in magic packet mode magic packet circuit 116 of phy 108 monitors the data produced by phy core 112 for ingressing magic packets step 208 in some embodiments memory 118 stores a magic packet pattern that magic packet circuit 116 compares to the data produced by phy core 112.