4.0.0.0 - 4.255.255.255 BBN Planet (NET-SATNET) 4.1.24.0 - 4.1.24.7 Netect (NETBLK-NETECT-24-17) 4.1.24.16 - 4.1.24.23 Pacific Telesis Group (NETBLK-PTG-24-17) 4.1.24.40 - 4.1.24.47 Cambridge Technology Group (NETBLK-CTGROUP-24-17) 4.1.24.48 - 4.1.24.63 The United Way (NETBLK-UNITEDWAY-24-16)