i'm not sure but it may mean following: 1 = Ethernet (using Ethernet II or IEEE 802.3 Sub-Network Access Protocol [SNAP] encapsulation) 2 = Fiber Distributed Data Interchange (FDDI) 3 = Token Ring (IEEE 802.5) 4 = IEEE 802.11 Wireless LAN 5 = ATM (using LAN emulation [LANE] and Classical IP [CLIP] over ATM) 6 = Attached Resource Computing Network (ARCnet) 7 = Dedicated wide area network (WAN) links such as Dataphone Digital Service (DDS) and T-carrier (Fractional T1, T1, T3, E1, and E3)