How many hosts are in a /23 network?

A network with a /23 mask means that the first 23 bits of the address are for the network, and the remaining 9 bits are for hosts.

Number of addresses in such a network: 2^(32-23) = 2^9 = 512.

Out of these, 2 addresses are reserved: one for the network address, and the other for the broadcast address.

Thus, the number of available hosts is 512 - 2 = 510.