Explain how slash notation describes an Internet Protocol version 4 (IPv4) subnet, and use `192.168.10.1/24` to identify the subnet mask and the number of total addresses.

### Why this is right The `/24` prefix means that 24 of the 32 IPv4 bits identify the network. The remaining eight bits give $2^8=256$ possible address values. Writing those first 24 bits as a dotted-decimal mask gives `255.255.255.0`. ### The concept A subnet mask marks network bits with binary ones and host bits with binary zeroes. In `255.255.255.0`, the first three octets are the network portion and the last octet can vary. The subnet containing `192.168.10.1/24` therefore spans `192.168.10.0` to `192.168.10.255`. The first and last addresses identify the network and broadcast, so the total count is not the same as the conventional usable host count. ### What a good answer covers - `/24` means 24 network bits out of 32. - The equivalent mask is `255.255.255.0`. - Eight variable bits produce 256 total addresses. - The network and broadcast addresses are the first and last addresses in the stated block. ### Terms - **IPv4**: Internet Protocol version 4, an address format made of 32 bits. - **Slash notation**: A prefix-length form such as `/24` that states how many leading bits belong to the network. - **Subnet mask**: A 32-bit value that distinguishes network bits from host bits. - **Octet**: One eight-bit portion of an IPv4 address. ### Remember A larger prefix fixes more bits for the network and leaves fewer addresses inside each subnet.