Reserved IP Range Checker Calculator

Work out reserved ip range checker instantly with clear inputs, formula shown and shareable results.

About Reserved IP Range Checker Calculator

IANA maintains a special-purpose address registry covering roughly 15 IPv4 blocks that are not ordinary global unicast space. Some, like RFC 1918 ranges, are perfectly usable inside your own network; others such as 0.0.0.0/8, 127.0.0.0/8, 169.254.0.0/16, the documentation TEST-NETs and class E must never appear on an interface.

Formula

Special-purpose lookup

for each registry block: match if (address AND mask(prefix)) equals the block network; report the RFC and whether hosts may use it

Worked example

With the default values below, Reserved IP Range Checker Calculator returns Reservation status of Reserved / special purpose. Change any input above and every figure here is recalculated in your browser.

Inputs used

IPv4 address: 169.254.10.5
Checking modeone of All IANA special-purpose blocks, Only blocks unusable for hosts: All IANA special-purpose blocks

Results

Reservation status: Reserved / special purpose
Matching block: 169.254.0.0/16
Reference: RFC 3927 link-local
Assignable to hosts: No - do not assign to hosts

Step by step

1Values used
2Special-purpose lookup
3Reservation status= Reserved / special purpose
4Matching block= 169.254.0.0/16
5Reference= RFC 3927 link-local
6Assignable to hosts= No - do not assign to hosts

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why avoid 192.0.2.0/24 in a lab?

It is reserved for documentation. Real traffic to it may be dropped or reused elsewhere, and copying examples verbatim into production causes confusing failures.

Are RFC 1918 addresses reserved or usable?

Both. They are reserved from the global routing table but explicitly intended for use inside private networks behind NAT.