Grade 12/13 - IP address classes
IP address classes Class 1 st Octet Decimal Range 1 st Octet High Order Bits Network/Host ID (N=Network, H=Host) Default Subnet Mask Number of Networks Hosts per Network (Usable Addresses) A 1 – 126* 0 N.H.H.H 255.0.0.0 126 (2 7 – 2) 16,777,214 (2 24 – 2) B 128 – 191 10 N.N.H.H 255.255.0.0 16,382 (2 14 – 2) 65,534 (2 16 – 2) C 192 – 223 110 N.N.N.H 255.255.255.0 2,097,150 (2 21 – 2) 254 (2 8 – 2) D 224 – 239 1110 Reserved for Multicasting E 240 – 254 1111 Experimental; used for research Note: Class A addresses 127.0.0.0 to 127.255.255.255 cannot be used and is reserved for loopback and diagnostic functions. Private IP Addresses Class Private Networks Subnet Mask Address Range A 10.0.0.0 ...