Read IP Subnets and CIDR

CIDR states how many leading address bits belong to a network prefix. The remaining bits determine the size of that address block.

Work through the task

1. Enter a host address and explicit prefix, such as the documentation address 192.0.2.130/26. The entered host and derived network are shown separately.
2. For IPv4 /26, 6 bits remain: 2^6 gives 64 addresses. The network is .128 and the conventional directed broadcast is .191.
3. Use the applicable convention. A /31 point-to-point link uses both endpoints; a /32 identifies one address. These are not ordinary multi-host LAN ranges.
4. For IPv6, use the exact total address count and prefix boundaries. Longer prefixes can split the block into equal smaller subnets without enumerating every host.

Checked examples

Calculation method

Address count is 2 raised to the number of host bits: 32 minus prefix for IPv4, or 128 minus prefix for IPv6. Clearing those host bits gives the network; setting them gives the range end. IPv6 has no broadcast address. The tool uses exact integer address arithmetic.

Assumptions and limits

Counts do not prove assignability, routing or reachability. Gateway choice, special-use blocks, operating systems and network policy can impose further constraints. Subdivision is equal-size, not VLSM. The paged list is explicitly a subset; no DNS lookup or network scan is performed.