CIDR Subnet Calculator

import ipaddress

def cidr_info(cidr: str) -> dict:
    network = ipaddress.ip_network(cidr, strict=False)
    return {
        "network_address": str(network.network_address),
        "broadcast_address": str(network.broadcast_address),
        "subnet_mask": str(network.netmask),
        "prefix_length": network.prefixlen,
        "total_addresses": network.num_addresses,
        "usable_hosts": max(0, network.num_addresses - 2),
        "first_host": str(network.network_address + 1),
        "last_host": str(network.broadcast_address - 1),
    }

# Example
info = cidr_info("192.168.1.0/24")
for k, v in info.items():
    print(f"{k}: {v}")

# Check if IP is in network
net = ipaddress.ip_network("10.0.0.0/8", strict=False)
ip = ipaddress.ip_address("10.5.20.1")
print(f"10.5.20.1 in 10.0.0.0/8: {ip in net}")