subnet_calc
// CIDR visualizer · binary breakdown · subnet planner · IPv4 vs IPv6
32-bit binary representation
binary · network bits (cyan) · host bits (green)
network bits host bits
network metrics
bit allocation
first usable hosts
    IPv4 32-bit exhausted
    address bits32
    total addresses~4.3 billion
    formatdotted decimal
    example192.168.1.1
    private ranges10.x · 172.16–31.x · 192.168.x
    nat requiredyes — for private IPs
    statuspool exhausted
    IPv6 128-bit active rollout
    address bits128
    total addresses3.4 × 10³⁸
    formatcolon-separated hex
    example2001:db8::1
    private rangesfc00::/7 (ULA)
    nat requiredno — end-to-end routing
    statusactive rollout
    address space comparison
    IPv4 — 32 bits — 2³² 4,294,967,296 addresses
    IPv6 — 128 bits — 2¹²⁸ 3.4 × 10³⁸ addresses

    // IPv6 has 2⁹⁶ × more addresses than IPv4 — roughly 79 octillion times larger

    IPv6 address anatomy
    example: 2001:0db8:85a3:0000:8a2e:0370:7334
    2001:0db8:85a3 : 0000 : 8a2e:0370:7334
    global routing prefix — 48 bits subnet ID — 16 bits interface ID — 64 bits