IPv4 から IPv6 への変換ツール
ガイド
IPv4 から IPv6 への変換ツール
Convert any IPv4 address into every standard IPv6 representation in one click. The tool generates the IPv4-mapped form used by dual-stack sockets, the 6to4 prefix that delegates a /48 to a public IPv4, the deprecated IPv4-compatible form kept for legacy lookups, and the reverse DNS PTR record under ip6.arpa. Each result is RFC-precise so you can paste it straight into firewall rules, BGP filters, or DNS zone files without hand-editing nibbles.
使用方法
- Type or paste an IPv4 address (for example
192.168.1.1または8.8.8.8). - The tool validates the four octets and instantly fills every IPv6 representation.
- Click the copy icon next to any field to put that representation on your clipboard.
- Use the Reset button to clear inputs and outputs.
機能
- IPv4-mapped IPv6 (RFC 4291) – dotted, hex-compressed, and fully expanded forms for dual-stack sockets.
- 6to4 (RFC 3056) – the
2002::/16/48 prefix and a ready-to-use first host inside it. - IPv4-compatible (deprecated) – kept for parsing legacy configs and historical PCAPs.
- Reverse DNS – nibble-reversed PTR record under
ip6.arpafor the IPv4-mapped address. - Instant client-side conversion – nothing leaves your browser, no API call, no logging.
- Strict validation – rejects malformed octets and leading zeros so the IPv6 output is always RFC-correct.
よくある質問
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What is an IPv4-mapped IPv6 address?
An IPv4-mapped IPv6 address embeds a 32-bit IPv4 address in the low-order bits of an IPv6 address with the prefix ::ffff:0:0/96. Defined in RFC 4291, it lets a single dual-stack socket accept both IPv4 and IPv6 traffic without separate listeners.
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How does the 6to4 transition mechanism work?
6to4 (RFC 3056) takes any public IPv4 address and produces a /48 IPv6 prefix under 2002::/16 by concatenating the prefix with the 32-bit IPv4 address. This lets an IPv4-only host route IPv6 packets to other 6to4 sites through anycast relays, without explicit tunnel configuration.
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Why is the IPv4-compatible IPv6 format deprecated?
IPv4-compatible IPv6 addresses (::a.b.c.d) were originally proposed for transparent IPv4-IPv6 transition, but they were never widely deployed and were formally deprecated by RFC 4291. Modern transition mechanisms use IPv4-mapped addresses for sockets and 6to4 or NAT64 for routing.
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How is reverse DNS for IPv6 different from IPv4?
IPv6 reverse DNS uses the ip6.arpa zone with each of the 32 hex nibbles reversed and dot-separated, while IPv4 uses in-addr.arpa with four reversed decimal octets. The longer label chain means IPv6 PTR records are typically delegated in /4 nibble boundaries rather than the /8 byte boundaries used for IPv4.
