If you're unable to access IPv6-only websites, you're not alone. This is one of the most common networking issues users face as the internet transitions from IPv4 to IPv6. Unlike websites that support both protocols (dual-stack), IPv6-only sites require working IPv6 connectivity to access them at all. This guide explains why you might be unable to reach these sites and provides comprehensive troubleshooting steps.
Quick Diagnosis: Visit test-ipv6.run to instantly check your IPv6 connectivity status and identify potential issues.
IPv4 and IPv6 are completely separate, incompatible protocols. If you only have IPv4 connectivity, you cannot reach IPv6-only websites - period. It's like trying to call a phone number in a different country without the right dialing codes or infrastructure. The two protocols don't translate or convert between each other automatically.
When you try to access an IPv6-only website, your browser performs a DNS lookup and receives only AAAA records (IPv6 addresses). If your network doesn't support IPv6, the connection simply fails.
Symptoms: Complete inability to reach any IPv6 sites, test-ipv6.run shows "IPv4 Only"
This is the most common issue. Many ISPs, especially in certain regions, still don't provide IPv6 service to residential customers. As of 2025, IPv6 adoption varies dramatically by country and provider. Without IPv6 support from your ISP, you cannot access IPv6-only resources.
What's happening: Your network simply doesn't have an IPv6 address assigned, so your device can't communicate using the IPv6 protocol.
Symptoms: Long timeouts when accessing websites, intermittent failures, test-ipv6.run shows "Broken IPv6"
This is arguably the most problematic scenario. Your device has IPv6 enabled and an IPv6 address assigned, but something in the network path is broken. Instead of connections failing quickly and falling back to IPv4, they timeout slowly (often 30-60 seconds), creating a terrible user experience.
What's happening: Your browser tries IPv6 first (as it should), but packets are getting lost somewhere between your device and the destination. The connection eventually times out, and only then does your browser try IPv4 (if available).
Symptoms: Some IPv6 sites work while others don't, "Server not found" errors
DNS issues can prevent your device from even obtaining the IPv6 address of a website. This can happen when:
What's happening: Your browser can't translate the domain name into an IPv6 address, so it doesn't know where to connect.
Symptoms: IPv6 works intermittently, different results at different times
Several ISP-level issues can prevent IPv6 connectivity:
What's happening: The infrastructure between you and the internet doesn't properly support IPv6 traffic.
Symptoms: Other devices on the same network can access IPv6 but yours can't
Your specific device might have:
What's happening: Your device itself isn't properly configured for IPv6, even though the network supports it.
Symptoms: Ping works but web browsing doesn't, or specific applications fail
Firewalls can block IPv6 traffic in several ways:
What's happening: Security software is preventing IPv6 packets from reaching their destination or blocking responses from coming back.
Symptoms: Direct connection works but connection through router fails
Home routers can cause IPv6 problems:
What's happening: Your router acts as a barrier preventing IPv6 traffic from flowing properly.
Visit test-ipv6.run immediately. This comprehensive testing tool will:
The results will tell you exactly which category of problem you're facing.
Windows:
ipconfig /all
Linux/macOS:
ifconfig -a
# or
ip -6 addr show
What to look for:
Ping Google's IPv6 DNS:
Windows:
ping -6 2001:4860:4860::8888
Linux/macOS:
ping6 2001:4860:4860::8888
If this fails, you don't have working IPv6 internet connectivity.
Test DNS resolution:
Windows:
nslookup -type=AAAA ipv6.google.com
ping -6 ipv6.google.com
Linux/macOS:
dig AAAA ipv6.google.com
ping6 ipv6.google.com
This tests whether DNS is returning IPv6 addresses and whether you can reach them.
Windows:
tracert -6 ipv6.google.com
Linux/macOS:
traceroute6 ipv6.google.com
This shows where packets are getting lost. If it fails at the first hop (your router), the problem is local. If it fails further along, it's an ISP or upstream issue.
Windows:
Linux:
sudo ip6tables -L -n -v
macOS:
sudo pfctl -s rules
Look for DROP or REJECT rules affecting IPv6 traffic.
Outdated drivers and firmware can have IPv6 bugs:
Ensure your DNS servers support IPv6:
Good IPv6-capable DNS servers:
2001:4860:4860::8888 and 2001:4860:4860::88442606:4700:4700::1111 and 2606:4700:4700::10012620:fe::fe and 2620:fe::9Configure these in your network settings if your ISP's DNS servers are problematic.
To isolate the problem:
If IPv6 works on other networks, the problem is with your home network configuration.
If you've determined your ISP doesn't provide IPv6:
If your ISP doesn't provide native IPv6, you can use a tunnel broker service:
Note: Tunnels add complexity and latency. They're a workaround, not an ideal solution.
Configuration requirements:
Windows:
netsh int ipv6 reset
netsh winsock reset
ipconfig /flushdns
Then restart your computer.
Linux:
sudo systemctl restart NetworkManager
# or
sudo /etc/init.d/networking restart
macOS:
sudo dscacheutil -flushcache
sudo killall -HUP mDNSResponder
If you have broken IPv6 that can't be fixed, disabling it may improve your browsing experience by eliminating timeout delays. However, this prevents you from accessing IPv6-only sites entirely.
Note: This should only be temporary while you work with your ISP to fix the underlying problem.
You might wonder why anyone would create an IPv6-only site. Reasons include:
As the internet continues transitioning to IPv6, encountering IPv6-only resources will become more common, not less.
Inability to reach IPv6-only websites stems from a variety of causes: no IPv6 support from your ISP, broken IPv6 configuration, DNS issues, firewall blocking, or device configuration problems. The first step is always to test your connectivity comprehensively.
Visit test-ipv6.run now to diagnose your specific situation. The test provides detailed results showing exactly what works and what doesn't, along with a readiness score. Armed with this information, you can follow the appropriate troubleshooting steps outlined in this guide.
Remember: working IPv6 connectivity is increasingly important as the internet evolves. Whether you're unable to access IPv6-only sites today or simply want to ensure you're ready for tomorrow's internet, proper IPv6 configuration is worth the effort.