{
  "_about": "IANA IPv4 and IPv6 Special-Purpose Address Registries (RFC 6890 and updates), plus a few supplementary well-known blocks that live in other registries. lib/subnet.js reads this file; it embeds no copy of its own.",
  "_sources": {
    "ipv4": "https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry-1.csv",
    "ipv6": "https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry-1.csv",
    "supplementary": "IANA IPv4 Multicast Address Space Registry (RFC 5771), IPv6 Addressing Architecture (RFC 4291), RFC 3879"
  },
  "_retrieved": "2026-10-02",
  "_provenance": "Downloaded directly from IANA. Exact CSV snapshots and SHA-256 hashes are retained; crosscheck.py checks their fields offline.",
  "_fields": "block: CIDR; name and rfc: IANA fields; globallyReachable: IANA column (null for N/A). analyze() classifies the input address by its most specific block.",
  "ipv4": [
    {
      "block": "0.0.0.0/8",
      "name": "\"This network\"",
      "rfc": "RFC 791",
      "globallyReachable": false
    },
    {
      "block": "0.0.0.0/32",
      "name": "\"This host on this network\"",
      "rfc": "RFC 1122",
      "globallyReachable": false
    },
    {
      "block": "10.0.0.0/8",
      "name": "Private-Use",
      "rfc": "RFC 1918",
      "globallyReachable": false
    },
    {
      "block": "100.64.0.0/10",
      "name": "Shared Address Space",
      "rfc": "RFC 6598",
      "globallyReachable": false
    },
    {
      "block": "127.0.0.0/8",
      "name": "Loopback",
      "rfc": "RFC 1122",
      "globallyReachable": false
    },
    {
      "block": "169.254.0.0/16",
      "name": "Link Local",
      "rfc": "RFC 3927",
      "globallyReachable": false
    },
    {
      "block": "172.16.0.0/12",
      "name": "Private-Use",
      "rfc": "RFC 1918",
      "globallyReachable": false
    },
    {
      "block": "192.0.0.0/24",
      "name": "IETF Protocol Assignments",
      "rfc": "RFC 6890",
      "globallyReachable": false
    },
    {
      "block": "192.0.0.0/29",
      "name": "IPv4 Service Continuity Prefix",
      "rfc": "RFC 7335",
      "globallyReachable": false
    },
    {
      "block": "192.0.0.8/32",
      "name": "IPv4 dummy address",
      "rfc": "RFC 7600",
      "globallyReachable": false
    },
    {
      "block": "192.0.0.9/32",
      "name": "Port Control Protocol Anycast",
      "rfc": "RFC 7723",
      "globallyReachable": true
    },
    {
      "block": "192.0.0.10/32",
      "name": "Traversal Using Relays around NAT Anycast",
      "rfc": "RFC 8155",
      "globallyReachable": true
    },
    {
      "block": "192.0.0.170/32",
      "name": "NAT64/DNS64 Discovery",
      "rfc": "RFC 8880, RFC 7050",
      "globallyReachable": false
    },
    {
      "block": "192.0.0.171/32",
      "name": "NAT64/DNS64 Discovery",
      "rfc": "RFC 8880, RFC 7050",
      "globallyReachable": false
    },
    {
      "block": "192.0.2.0/24",
      "name": "Documentation (TEST-NET-1)",
      "rfc": "RFC 5737",
      "globallyReachable": false
    },
    {
      "block": "192.31.196.0/24",
      "name": "AS112-v4",
      "rfc": "RFC 7535",
      "globallyReachable": true
    },
    {
      "block": "192.52.193.0/24",
      "name": "AMT",
      "rfc": "RFC 7450",
      "globallyReachable": true
    },
    {
      "block": "192.88.99.0/24",
      "name": "Deprecated (6to4 Relay Anycast)",
      "rfc": "RFC 7526",
      "globallyReachable": null
    },
    {
      "block": "192.88.99.2/32",
      "name": "6a44-relay anycast address",
      "rfc": "RFC 6751",
      "globallyReachable": false
    },
    {
      "block": "192.168.0.0/16",
      "name": "Private-Use",
      "rfc": "RFC 1918",
      "globallyReachable": false
    },
    {
      "block": "192.175.48.0/24",
      "name": "Direct Delegation AS112 Service",
      "rfc": "RFC 7534",
      "globallyReachable": true
    },
    {
      "block": "198.18.0.0/15",
      "name": "Benchmarking",
      "rfc": "RFC 2544",
      "globallyReachable": false
    },
    {
      "block": "198.51.100.0/24",
      "name": "Documentation (TEST-NET-2)",
      "rfc": "RFC 5737",
      "globallyReachable": false
    },
    {
      "block": "203.0.113.0/24",
      "name": "Documentation (TEST-NET-3)",
      "rfc": "RFC 5737",
      "globallyReachable": false
    },
    {
      "block": "240.0.0.0/4",
      "name": "Reserved",
      "rfc": "RFC 1112",
      "globallyReachable": false
    },
    {
      "block": "255.255.255.255/32",
      "name": "Limited Broadcast",
      "rfc": "RFC 8190, RFC 919",
      "globallyReachable": false
    }
  ],
  "ipv6": [
    {
      "block": "::1/128",
      "name": "Loopback Address",
      "rfc": "RFC 4291",
      "globallyReachable": false
    },
    {
      "block": "::/128",
      "name": "Unspecified Address",
      "rfc": "RFC 4291",
      "globallyReachable": false
    },
    {
      "block": "::ffff:0:0/96",
      "name": "IPv4-mapped Address",
      "rfc": "RFC 4291",
      "globallyReachable": false
    },
    {
      "block": "64:ff9b::/96",
      "name": "IPv4-IPv6 Translat.",
      "rfc": "RFC 6052",
      "globallyReachable": true
    },
    {
      "block": "64:ff9b:1::/48",
      "name": "IPv4-IPv6 Translat.",
      "rfc": "RFC 8215",
      "globallyReachable": false
    },
    {
      "block": "100::/64",
      "name": "Discard-Only Address Block",
      "rfc": "RFC 6666",
      "globallyReachable": false
    },
    {
      "block": "100:0:0:1::/64",
      "name": "Dummy IPv6 Prefix",
      "rfc": "RFC 9780",
      "globallyReachable": false
    },
    {
      "block": "2001::/23",
      "name": "IETF Protocol Assignments",
      "rfc": "RFC 2928",
      "globallyReachable": false
    },
    {
      "block": "2001::/32",
      "name": "TEREDO",
      "rfc": "RFC 4380, RFC 8190",
      "globallyReachable": null
    },
    {
      "block": "2001:1::1/128",
      "name": "Port Control Protocol Anycast",
      "rfc": "RFC 7723",
      "globallyReachable": true
    },
    {
      "block": "2001:1::2/128",
      "name": "Traversal Using Relays around NAT Anycast",
      "rfc": "RFC 8155",
      "globallyReachable": true
    },
    {
      "block": "2001:1::3/128",
      "name": "DNS-SD Service Registration Protocol Anycast",
      "rfc": "RFC 9665",
      "globallyReachable": true
    },
    {
      "block": "2001:2::/48",
      "name": "Benchmarking",
      "rfc": "RFC 5180",
      "globallyReachable": false
    },
    {
      "block": "2001:3::/32",
      "name": "AMT",
      "rfc": "RFC 7450",
      "globallyReachable": true
    },
    {
      "block": "2001:4:112::/48",
      "name": "AS112-v6",
      "rfc": "RFC 7535",
      "globallyReachable": true
    },
    {
      "block": "2001:10::/28",
      "name": "Deprecated (previously ORCHID)",
      "rfc": "RFC 4843",
      "globallyReachable": null
    },
    {
      "block": "2001:20::/28",
      "name": "ORCHIDv2",
      "rfc": "RFC 7343",
      "globallyReachable": true
    },
    {
      "block": "2001:30::/28",
      "name": "Drone Remote ID Protocol Entity Tags (DETs) Prefix",
      "rfc": "RFC 9374",
      "globallyReachable": true
    },
    {
      "block": "2001:db8::/32",
      "name": "Documentation",
      "rfc": "RFC 3849",
      "globallyReachable": false
    },
    {
      "block": "2002::/16",
      "name": "6to4",
      "rfc": "RFC 3056",
      "globallyReachable": null
    },
    {
      "block": "2620:4f:8000::/48",
      "name": "Direct Delegation AS112 Service",
      "rfc": "RFC 7534",
      "globallyReachable": true
    },
    {
      "block": "3fff::/20",
      "name": "Documentation",
      "rfc": "RFC 9637",
      "globallyReachable": false
    },
    {
      "block": "5f00::/16",
      "name": "Segment Routing (SRv6) SIDs",
      "rfc": "RFC 9602",
      "globallyReachable": false
    },
    {
      "block": "fc00::/7",
      "name": "Unique-Local",
      "rfc": "RFC 4193, RFC 8190",
      "globallyReachable": false
    },
    {
      "block": "fe80::/10",
      "name": "Link-Local Unicast",
      "rfc": "RFC 4291",
      "globallyReachable": false
    }
  ],
  "supplementary": [
    {
      "block": "224.0.0.0/4",
      "name": "Multicast",
      "rfc": "RFC 5771",
      "globallyReachable": null
    },
    {
      "block": "ff00::/8",
      "name": "Multicast",
      "rfc": "RFC 4291",
      "globallyReachable": null
    },
    {
      "block": "fec0::/10",
      "name": "Site-Local (deprecated)",
      "rfc": "RFC 3879",
      "globallyReachable": null
    }
  ],
  "_sha256": {
    "ipv4": "e3e39e76d00b1677335db8e9a805c7b9480ea2f4dc9e33f0b93cd3a905128d73",
    "ipv6": "775feea0621dec8735a44fbf30f762e721e8f0a1b3ab7eb341961a88cfce2139"
  }
}