PacketFlo IPv6 Connectivity API

Cost: 2 credits per request

Check whether a domain or host actually works over IPv6 from PacketFlo's infrastructure, including DNS AAAA discovery, TCP handshake, HTTPS/TLS negotiation, and IPv4 comparison. Costs 2 credits per check.

Test in Web Console

Parameter	Type	Required	Description
`host`	string	Yes	Domain, hostname, or full URL to test for IPv6 reachability.

Example request

curl "https://packetflo.io/api/v1/ipv6?host=example.com&api_key=YOUR_API_KEY"

Example response

{
  "ok": true,
  "data": {
    "host": "example.com",
    "targetUrl": "https://example.com",
    "protocol": "https:",
    "port": 443,
    "verdict": "IPv6 Working",
    "verdictTone": "ok",
    "verdictExplanation": "example.com is fully reachable and responsive over IPv6 from PacketFlo.",
    "ipv4WorksIpv6Fails": false,
    "dualStackWorking": true,
    "aaaaRecordCount": 2,
    "aRecordCount": 2,
    "addresses": [
      {
        "address": "2606:2800:21f:cb07:6820:80da:af6b:8b2c",
        "ttl": 300,
        "tcp": { "port": 443, "reachable": true, "status": "Open", "latencyMs": 24, "error": null },
        "http": { "working": true, "status": 200, "statusText": "OK", "protocol": "HTTP/2", "tlsVersion": "TLSv1.3", "cipher": "TLS_AES_256_GCM_SHA384", "responseTimeMs": 118, "error": null },
        "ping": { "reachable": false, "latencyMs": null, "blocked": true }
      }
    ],
    "ipv4Comparison": {
      "hasDns": true,
      "ip": "93.184.215.14",
      "ttl": 300,
      "tcpReachable": true,
      "tcpStatus": "Open",
      "tcpLatencyMs": 31,
      "httpWorking": true,
      "httpStatus": 200,
      "httpProtocol": "HTTP/2",
      "tlsVersion": "TLSv1.3",
      "responseTimeMs": 122
    },
    "comparisonSummary": "Dual-stack connectivity is working. Both IPv4 and IPv6 are active and responsive.",
    "icmpSummary": "IPv6 is working. ICMP appears to be blocked by a firewall, but the service itself is reachable over IPv6.",
    "checkedAt": "2026-10-01T00:00:00.000Z"
  },
  "meta": { "tool": "ipv6", "version": "v1" }
}

Reading the result

Examine verdict and dualStackWorking. IPv6 Working confirms both TCP and HTTP/HTTPS succeeded over IPv6. A prominent warning applies when ipv4WorksIpv6Fails is true.

Response fields

Field	What it tells you
`verdict` / `verdictTone`	Diagnostic conclusion ('IPv6 Working', 'IPv6 Partially Reachable', 'IPv6 Connectivity Failed', 'IPv6 Application Connectivity Failed', or 'IPv6 Not Configured').
`ipv4WorksIpv6Fails` / `dualStackWorking`	Flags comparing IPv4 reachability against IPv6.
`addresses`	Array of tested IPv6 addresses, each containing individual TCP, HTTP/TLS, and ICMP probe results.
`ipv4Comparison`	Summary of IPv4 DNS, TCP latency, and HTTP status for comparison.
`comparisonSummary` / `icmpSummary`	Plain-text diagnostic summaries of dual-stack behavior and ICMP echo response.

Scope and limits

Tests DNS AAAA resolution, TCP connection on the destination port, and TLS/HTTP negotiation directly over IPv6 from PacketFlo's server. Does not rely on Happy Eyeballs fallback. Up to 4 IPv6 addresses are tested per host.

Authentication and errors

Send your key in the x-api-key header, or the supported api_key query parameter. Each request uses 2 credits from the key's shared 300-credit rolling 24-hour budget. Credits are charged before parameter validation. Successful responses and quota errors include usage headers; GET and OPTIONS support CORS.

API status	Meaning
`200`	The diagnostic returned a result in `data`, with `ok: true` and version information in `meta`. Read the diagnostic fields to determine the target's condition.
`400`	Invalid or blocked input, or a lookup/check failure that could not be returned as a diagnostic result. Read `error` for details.
`401`	Missing, invalid or revoked API key.
`429`	The request would exceed the key's available credit budget.

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