What IP am I using?
Your public IPv4 and IPv6 are detected, then expanded into the CIDR ranges that contain each address.
IPv4: zoom out from one address
The smaller the prefix length, the bigger the network.
IPv6: the same idea, much larger numbers
Common checkpoints are /128, /64, /56, /48 and /32.
What does CIDR actually mean?
A CIDR prefix says how many leading bits are fixed. More fixed bits = a smaller range. Fewer fixed bits = a larger range.
A /32 is one IPv4 address. A /128 is one IPv6 address. These are ranges, not promises about who owns every address inside them.
Why range size matters
| Prefix | Approx. size | Typical implication |
|---|---|---|
/32 IPv4 | 1 address | Exact host-level match. |
/24 IPv4 | 256 addresses | Much broader allowlist / blocklist scope. |
/16 IPv4 | 65,536 addresses | Large network; usually too broad for a host-specific rule. |
/128 IPv6 | 1 address | Exact address match. |
/64 IPv6 | 264 addresses | A very large subnet; a common IPv6 LAN/subnet boundary. |
/48 IPv6 | 280 addresses | A common site/customer prefix; it contains many /64 subnets. |
/32 IPv6 | 296 addresses | Very large allocation / aggregate; far broader than a single site subnet. |
Allowlisting
A narrow prefix reduces the number of addresses that receive access. A broad prefix trusts many addresses at once.
Blocking
A broad prefix blocks more addresses. That can catch more unwanted traffic, but can also affect unrelated users.
Privacy
An IP range can describe a network boundary, but it does not by itself prove a person's identity or exact physical location.