IPv4 and IPv6 are two versions of the Internet Protocol. A dual-stack device can use both, and the address a website shows belongs to the connection that actually reached it. Having IPv6 does not automatically make a connection faster or safer.
The differences that matter
| Property | IPv4 | IPv6 |
|---|---|---|
| Address size | 32 bits | 128 bits |
| Example | 192.0.2.25 | 2001:db8::25 |
| Typical home setup | Private LAN behind router NAT | Routed prefixes with a stateful firewall |
| Broadcast | Used on ordinary LAN subnets | Uses multicast instead |
The example addresses above are for documentation. Do not configure them as real Internet destinations. IPv6 expands addressing capacity; it does not replace DNS, TCP, Wi-Fi, or the need to protect services.
Why two IP checks can disagree
Imagine your laptop has a private IPv4 address and a global IPv6 address. An IPv4-only website sees the router's public IPv4 address. An IPv6-capable website may see one of the laptop's IPv6 addresses. Both observations can be correct. Your operating system and browser choose from the available paths; they do not have to use the same family for every destination.
A VPN can complicate the picture by tunneling one family, both families, or neither for a particular route. Compare the same destination before and after connecting. A changed address confirms a changed observed path, but does not prove that every application uses the tunnel.
Check each family separately
# Windows: test a hostname that publishes both families
ping -4 example.com
ping -6 example.com
# Force the connection family when checking your public IP
curl -4 https://thisismyip.com/ip
curl -6 https://thisismyip.com/ipThe curl commands only work when both your connection and this site's hosting support the requested family. A failure is a starting point, not proof that your device lacks IPv6: the destination, DNS answer, firewall, or route may be responsible. Compare results with another known dual-stack destination and inspect your local addresses.
Should you disable IPv6?
Start by fixing the broken path. Record DNS answers, gateway reachability, VPN behavior, and whether the failure affects all destinations or one service. Disabling an entire family can hide the symptom while leaving the underlying configuration wrong. For a temporary diagnostic comparison, record the original setting and restore it afterward.
When hosting a service, test inbound IPv4 and IPv6 independently. An IPv4 port-forward rule does not create an IPv6 firewall rule. Publish an AAAA record only after confirming that the service listens on IPv6 and that the intended traffic can reach it.
Put it into practice
References & further reading
Protocol standards and official documentation supporting this guide. Device menus and provider policies vary; use the documentation for your equipment when applying a change.