Is X.Y.Z.0 a valid IP address?

It depends on the subnet of the IP address in question. In general, the first and last addresses in a subnet are used as the network identifier and broadcast address, respectively. All other addresses in the subnet can be assigned to hosts on that subnet. For example, IP addresses of networks with subnet masks of … Read more

How does IPv4 Subnetting Work?

IP subnets exist to allow routers to choose appropriate destinations for packets. You can use IP subnets to break up larger networks for logical reasons (firewalling, etc), or physical need (smaller broadcast domains, etc). Simply put, though, IP routers use your IP subnets to make routing decisions. Understand how those decisions work, and you can … Read more