In Internet Protocol version 4 (IPv4), a unicast address in the range 1.0.0.1 to 126.255.255.254. Class A addresses are identified by a beginning 0 bit.The next 7 bits identify the specific network, with 128 (2 7 ) theoretically possible. As addresses 0 and 127 are reserved, 126 network addresses remain available for assignment. As the specific host on the network is identified in bits 8 through 31, as many as 16,777,214 (2 24 -2) hosts can be supported per network. Class A addresses are intended for very large networks supporting a great number of host computers. See also binary notation, bit, host, IPv4, network, and unicast.