Shared-IP clues — what your address can and cannot prove.

How can I investigate whether my connection uses shared IPv4?

Compare your router’s WAN IPv4 with the public IPv4 used by the same connection at approximately the same time, accounting for proxies or VPNs. The lookup supplies network context; the provider must confirm its NAT arrangement.

Source availability depends on the current deployment and each returned record. These review dates do not establish when a particular IP was observed. Method axis-scope-2026-09-15 · Score ipjury-score-v3.

A public IP lookup cannot, on its own, prove that you share an exit with other subscribers. It can show the network role, address scope and published evidence. To investigate carrier-grade NAT, compare those clues with the WAN address shown by your own router and ask your provider to confirm its setup.

What carrier-grade NAT changes

A provider can translate several customers' connections onto public IPv4 addresses at a carrier gateway. A website then sees the gateway's public address rather than the address assigned to the customer's router. The number of customers, allocation policy and mapping lifetime are provider-specific. Neither an ASN name nor a mobile-network label discloses those details.

An address-based rate limit can consequently affect several unrelated people. Cloudflare describes detecting CGNAT to reduce such collateral effects. That mechanism is a reason to investigate shared egress, not proof that CGNAT caused your particular CAPTCHA. Websites can also use account, browser, session and behaviour signals that this lookup does not observe.

Compare the right pair of addresses

1. Record the public IPv4 for this connection. Use the My IP action and note the time. An IPv6 result is not the IPv4 exit; comparing the two will not diagnose IPv4 NAT.
2. Read the WAN or Internet IPv4 in your router's status page. Do not use your laptop's local address or the router's LAN address. No router password or screenshot needs to be uploaded to IPJury.
3. Compare them at approximately the same time. A WAN address in 100.64.0.0/10 and a different public IPv4 is consistent with an upstream translation arrangement. An RFC 1918 private WAN address can also reflect another router under your control, so a mismatch alone does not distinguish provider CGNAT from double NAT.
4. Account for the path being tested. A browser proxy, VPN, corporate gateway or split-tunnel setup can make the browser's exit differ from the router's. Record that context rather than treating every mismatch as CGNAT.
5. Ask the provider for confirmation. Ask whether your service uses carrier-grade NAT, whether a public IPv4 option exists, and whether its static-address offering is dedicated. A static address and an exclusive address are different promises.

What the IPJury record contributes

Network role identifies source-reported mobile, residential, business or hosting context. ASN and prefix identify the network or block named by a source, not its subscriber count. PTR can contain operator naming clues, but a name containing “pool” or “nat” is not independent proof of shared service.

Read abuse evidence separately. A listing can name the public address without identifying which subscriber generated traffic. A prefix-level observation applies at a different scope again. No finding in covered sources means no finding was returned for this check; it does not establish that the address is exclusive, safe or accepted by a platform. An unanswered or withheld source leaves an explicit gap.

A useful question to send to support

“At the recorded time, my router reported this WAN IPv4, while my browser used this public IPv4. I was using the following proxy or VPN setup, or none. Does this service use provider-side NAT, and is the public address shared with other subscribers?” Attach only the facts you intend to disclose. The IPJury report can support the network-identity part of that question; it cannot answer on the provider's behalf.