Subnet Calculator

Work out what an address block covers, divide it, and check a list of ranges against the assets in an open analysis.

Address or block

Try 10.0.0.0/24a block 10.0.0.7/24a host in one 10.0.0.0 255.255.255.0a dotted mask 2001:db8::/64IPv6

Divide into

2001:db8::/64

Documentation IPv6 Nothing typed here is looked up or stored.

Reserved for examples and documentation (RFC 5737 / RFC 3849). Not routable and not anybody's estate — an address from this space in a scan result is usually a placeholder.

Network address 2001:db8::

As an integer 42540766411282592856903984951653826560

Address range 2001:db8:: – 2001:db8::ffff:ffff:ffff:ffff

Range as integers 42540766411282592856903984951653826560 – 42540766411282592875350729025363378175

Total addresses 2^64 Reserved ones included

Usable hosts — Every address assignable

Prefix /64 64 network bits, 64 host

Netmask ffff:ffff:ffff:ffff::

Wildcard ::ffff:ffff:ffff:ffff

Reverse DNS zone 0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.

Boundaries Every address assignable

2001:db8::First usable 2001:db8::ffff:ffff:ffff:ffffLast usable

Range list — optional

Paste the ranges you use for exposure tagging. Commas, semicolons and newlines all work. This page reports what they cover and where they repeat themselves; open it from a running analysis to check them against your uploaded assets.