Reserved IP-address Some IP-addresses are reserved and can not be assigned to individual devices in the network. These are reserved addresses include network address that is used to identify the network and broadcast address used for sending broadcast packets to all devices on the network.
Network address: IP-address with binary zeros in all the host bits reserved for the network address. So, for Class A network IP-address is the address 10.0.0.0 network that is host 10.1.2.3. IP-address 172.16.0.0 is an example of the network address class, while 192.16.1.0 belongs to the class C IP-address used by the router to find a table IP-Routes location of the destination network. Appointed decimal numbers that fill the first two octets in a Class B network address
The last two octets contain zero, as these are designed for 16-bit addressing of hosts and used for end devices connected to the network. In IP-address 172.16.0.0 first two octets reserved for the network address; These octets are never used for addressing addresses connected devices. For example, the network 172.16.0.0 device can have IP-address 172.16.16.1. In this example, 172.16 is part of a network address, and 16.1 - hosts.
Directed broadcast address: To transfer data to all devices used in a particular network broadcast address (Directed Broadcast Address). All hosts bits in the broadcast IP-address filled in binary units
| Address block (CIDR) | Range | Number of Addresses | Scope | Purpose |
|---|---|---|---|---|
| 0.0.0.0/8 | 0.0.0.0 – 0.255.255.255 |
16,777,216 | software | Used for broadcast messages to the current ("this") network as specified by RFC 1700, page 4. |
| 10.0.0.0/8 | 10.0.0.0 – 10.255.255.255 |
16,777,216 | private network | Used for local communications within a private network as specified by RFC 1918. |
| 100.64.0.0/10 | 100.64.0.0 – 100.127.255.255 |
4,194,304 | private network | Used for communications between a service provider and its subscribers when using a Carrier-grade NAT, as specified by RFC 6598. |
| 127.0.0.0/8 | 127.0.0.0 – 127.255.255.255 |
16,777,216 | host | Used for loopback addresses to the local host, as specified by RFC 990. |
| 169.254.0.0/16 | 169.254.0.0 – 169.254.255.255 |
65,536 | subnet | Used for link-local addresses between two hosts on a single link when no IP address is otherwise specified, such as would have normally been retrieved from a DHCP server, as specified by RFC 3927. |
| 172.16.0.0/12 | 172.16.0.0 – 172.31.255.255 |
1,048,576 | private network | Used for local communications within a private network as specified by RFC 1918 |
| 192.0.0.0/24 | 192.0.0.0 – 192.0.0.255 |
256 | private network | Used for the IANA IPv4 Special Purpose Address Registry as specified by RFC 5736 |
| 192.0.2.0/24 | 192.0.2.0 – 192.0.2.255 |
256 | documentation | Assigned as "TEST-NET" in RFC 5737 for use solely in documentation and example source code and should not be used publicly. |
| 192.88.99.0/24 | 192.88.99.0 – 192.88.99.255 |
256 | Internet | Used by 6to4 anycast relays as specified by RFC 3068. |
| 192.168.0.0/16 | 192.168.0.0 – 192.168.255.255 |
65,536 | private network | Used for local communications within a private network as specified by RFC 1918. |
| 198.18.0.0/15 | 198.18.0.0 – 198.19.255.255 |
131,072 | private network | Used for testing of inter-network communications between two separate subnets as specified in RFC 2544. |
| 198.51.100.0/24 | 198.51.100.0 – 198.51.100.255 |
256 | documentation | Assigned as "TEST-NET-2" in RFC 5737 for use solely in documentation and example source code and should not be used publicly. |
| 203.0.113.0/24 | 203.0.113.0 – 203.0.113.255 |
256 | documentation | Assigned as "TEST-NET-3" in RFC 5737 for use solely in documentation and example source code and should not be used publicly. |
| 224.0.0.0/4 | 224.0.0.0 – 239.255.255.255 |
268,435,456 | Internet | Reserved for multicast assignments as specified in RFC 5771.
233.252.0.0/24 is assigned as "MCAST-TEST-NET" for use solely in documentation and example source code. |
| 240.0.0.0/4 | 240.0.0.0 – 255.255.255.254 |
268,435,455 | n/a | Reserved for future use, as specified by RFC 6890. |
| 255.255.255.255/32 | 255.255.255.255 | 1 | n/a | Reserved for the "limited broadcast" destination address, as specified by RFC 6890. |
| Address block (CIDR) | Range | Number of Addresses | scope | Purpose |
|---|---|---|---|---|
| ::/128 | :: | 1 | software | Unspecified address |
| ::1/128 | ::1 | 1 | host | loopback address to the local host. |
| ::ffff:0:0/96 | ::ffff:0.0.0.0 – ::ffff:255.255.255.255 | 232 | software | IPv4 mapped addresses |
| 100::/64 | 100:: – 100::ffff:ffff:ffff:ffff | 264 | Discard Prefix RFC 6666 | |
| 64:ff9b::/96 | 64:ff9b::0.0.0.0 – 64:ff9b::255.255.255.255 | 232 | global Internet | IPv4/IPv6 translation (RFC 6052) |
| 2001::/32 | 2001:: – 2001::ffff:ffff:ffff:ffff:ffff:ffff | 296 | global | Teredo tunneling |
| 2001:10::/28 | 2001:10:: – 2001:1f:ffff:ffff:ffff:ffff:ffff:ffff | 2100 | software | Deprecated (previously ORCHID) |
| 2001:20::/28 | 2001:20:: – 2001:2f:ffff:ffff:ffff:ffff:ffff:ffff | 2100 | software | ORCHIDv2 |
| 2001:db8::/32 | 2001:db8:: – 2001:db8:ffff:ffff:ffff:ffff:ffff:ffff | 296 | documentation | Addresses used in documentation |
| 2002::/16 | 2002:: – 2002:ffff:ffff:ffff:ffff:ffff:ffff:ffff | 2112 | global Internet | 6to4 |
| fc00::/7 | fc00:: – fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff | 2121 | private network | Unique local address |
| fe80::/10 | fe80:: - febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff | 2118 | link | Link-local address |
| ff00::/8 | ff00:: – ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff | 2120 | global Internet | Multicast |