A.the IP address B.the MAC address C.inetd D.port 80
A.24 B.126 C.128 D.254
A.255.255.128.0 (11111111.11111111.10000000.00000000) B.255.255.192.0 (11111111.11111111.11000000.00000000) C.255.255.224.0 (11111111.11111111.11100000.00000000) D.255.255.240.0 (11111111.11111111.11110000.00000000)