IP-Address Ranges

Overview of reserved IP-Address ranges for IPv4 and IPv6

In General

While IPv4 and IPv6 have different terminology, they share some concepts. Scope and Delivery schemes.

Both IP-Versions share the following delivery schemes:

one to one, the default
one to many, v6 had a huge Update there
usually inside the scope of a single network

Scope is a bit version dependant, usually you have:

These addresses are globally routable and assigned by the IANA and the local Internet registries.
These addresses are reserved for private use and you are free to use the in your own network, just be aware, that you can't use them on the internet.
These addresses always route back to the sending machine, usually localhost resolves to them.
These adresses are automatically assigned so that host on the same network can talk to each other.
These addresses are reserved for documentation purposes.
Other reserved
These adresses are reserved and have some conditions on when you are supposed to use them.

IPv6 Adress Ranges

By default IPv6 adresses are unassigned global unicast adresses and therefore reserved for future use. The IANA has a complete list with the IANA IPv6 Special-Purpose Address Registry.

Global Unicast (RFC 4291, Section 2.5.4)
Unique Local (Private) (RFC 4193)
fd00::/8 (with Random Global ID)
fc00::/8 (reserved for future use)
Loopback (RFC 4291, Section 2.5.3)
Link-Local (RFC 4291, Section 2.5.6
Documentation (RFC 3849)
Multicast (RFC 4291, Section 2.7)
IETF Protocol Assignments (RFC 6890)

Note: Site-Local IPv6 Unicast Addresses (RFC 4291, Section 2.5.7) have been deprecated in favour of Unique Local Addresses (RFC 4193) which are pretty similar, but better defined.

IPv4 Address Ranges

By default IPv4 adresses are adresses that fall in the global unicast category. The IANA has a complete List with the IANA IPv4 Special-Purpose Address Registry.

Private (RFC 1918)
Loopback (RFC 1122, Section Note that this is an entire network. Usually is used.
Link-Local (RFC 2927)
Documentation (RFC 5737) (TEST-NET-1) (TEST-NET-2) (TEST-NET-3)
Shared (RFC 6598)

used as Shared Address Space to accommodate the needs of Carrier-Grade NAT (CGN) devices.

Benchmarking (RFC 2544)
Multicast Multicast "Namespace" (RFC 1112) Automatic Multicast Tunneling (RFC 7450)
IETF Protocol Assignments (RFC 6890)


Broadcast addresses with IPv4 work by setting the host-part of the address to all ones (in the binary representation) they send to all hosts in the local network.

Note: In RFC 919 is defined as

broadcast to all of its immediate neighbors