Check this out...
[root@host /conf]# ifconfig
em0: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=481249b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,LRO,WOL_MAGIC,VLAN_HWFILTER,NOMAP>
ether 00:30:48:d5:c4:f1
media: Ethernet autoselect (1000baseT...