Reserved IP Ranges
RFC reserved IP address ranges reference. Covers private IPs (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback, link-local, multicast, and other special-purpose address blocks
IPv4Reserved IPv4 Address Ranges
| CIDR | Name | RFC | Description |
|---|---|---|---|
0.0.0.0/8 | This Network | RFC 791 | Current network (valid only as source address) |
0.0.0.0/32 | Unspecified Address | RFC 5735 | Unspecified address. Used by DHCP clients during initialization |
10.0.0.0/8 | Private (Class A) | RFC 1918 | Private network (Class A). For large internal networks |
100.64.0.0/10 | Shared Address Space | RFC 6598 | Shared address space for Carrier-Grade NAT (CGN) |
127.0.0.0/8 | Loopback | RFC 1122 | Loopback addresses. Used for localhost communication (127.0.0.1 is most common) |
169.254.0.0/16 | Link-Local | RFC 3927 | Link-local addresses. Auto-configured when no DHCP server is available (APIPA) |
172.16.0.0/12 | Private (Class B) | RFC 1918 | Private network (Class B). Range: 172.16.0.0 - 172.31.255.255 |
192.0.0.0/24 | IETF Protocol Assignments | RFC 6890 | IETF protocol assignments. Used for DS-Lite, NAT64, and other protocols |
192.0.2.0/24 | Documentation (TEST-NET-1) | RFC 5737 | Documentation and examples (TEST-NET-1). Used in docs and sample code |
192.88.99.0/24 | 6to4 Relay Anycast | RFC 3068 | 6to4 relay anycast (deprecated) |
192.168.0.0/16 | Private (Class C) | RFC 1918 | Private network (Class C). Most common in home and small office networks |
198.18.0.0/15 | Benchmarking | RFC 2544 | Network device benchmarking and testing |
198.51.100.0/24 | Documentation (TEST-NET-2) | RFC 5737 | Documentation and examples (TEST-NET-2) |
203.0.113.0/24 | Documentation (TEST-NET-3) | RFC 5737 | Documentation and examples (TEST-NET-3) |
224.0.0.0/4 | Multicast | RFC 5771 | Multicast addresses (224.0.0.0 - 239.255.255.255). For group communication |
240.0.0.0/4 | Reserved (Future Use) | RFC 1112 | Reserved for future use (240.0.0.0 - 255.255.255.254) |
255.255.255.255/32 | Limited Broadcast | RFC 919 | Limited broadcast address. Sends to all hosts on the local network |
IPv6Reserved IPv6 Address Ranges
| CIDR | Name | RFC | Description |
|---|---|---|---|
::1/128 | Loopback | RFC 4291 | IPv6 loopback address. Equivalent to 127.0.0.1 in IPv4 |
::/128 | Unspecified Address | RFC 4291 | IPv6 unspecified address. Equivalent to 0.0.0.0 in IPv4 |
::/0 | Default Route | RFC 5156 | Default route. Matches all IPv6 addresses |
::ffff:0:0/96 | IPv4-Mapped IPv6 | RFC 4291 | IPv4-mapped IPv6 addresses. Represents IPv4 addresses in IPv6 format |
64:ff9b::/96 | IPv4/IPv6 Translation | RFC 6052 | Well-known prefix for NAT64. IPv4/IPv6 translation |
100::/64 | Discard-Only | RFC 6666 | Discard-only address block. For blackhole routing |
2001::/32 | Teredo | RFC 4380 | Teredo tunneling. IPv6 connectivity through NATs |
2001:db8::/32 | Documentation | RFC 3849 | IPv6 documentation addresses. Used in documentation and examples |
2002::/16 | 6to4 | RFC 3056 | 6to4 tunneling addresses (deprecated) |
fc00::/7 | Unique Local Address (ULA) | RFC 4193 | Unique Local Addresses. Equivalent to IPv4 private addresses (RFC 1918) |
fe80::/10 | Link-Local | RFC 4291 | Link-local addresses. Used for communication on the same link (auto-configured) |
ff00::/8 | Multicast | RFC 4291 | IPv6 multicast addresses. For group communication |