Content of the article

Why IPv6 Leaks Are Breaking Your Anonymity Right Now

What IPv6 Traffic Is and Why VPNs Sometimes Ignore It

IPv6 stopped being theoretical years ago. By 2026, global adoption has surpassed 44-48% of all traffic, and in some countries, mobile networks operate IPv6-only using NAT64 and DNS64. Sounds perfect, but here’s the catch: many VPN setups are still built around IPv4 and simply overlook IPv6 unless you specifically enable support. That means some apps keep communicating via IPv6 outside the VPN tunnel—as if the VPN isn’t even there. Quietly, unnoticed, and without error pop-ups. That’s a pure leak.

Here’s a simple example. You connect to your VPN, see a fresh IPv4 address from the VPN provider, relax, and open your browser. The website requests an AAAA record and connects directly over IPv6 through your ISP. Your ISP’s IP is exposed, cookies stay intact, and you think you’re protected. Meanwhile, in another tab, WebRTC sends a STUN request and reveals your global IPv6 address. Graphs look fine, but your privacy’s compromised. Frustrating, right?

Where the Holes Appear: Dual-Stack, Happy Eyeballs, QUIC, and WebRTC

Leaks come from multiple sources. The network stack in 2026 actively uses the Happy Eyeballs strategy: the client tries IPv4 and IPv6 in parallel and picks the fastest response. If your VPN only covers IPv4, the direct IPv6 wins. Another factor: modern apps communicate over HTTP/3 on QUIC (which uses UDP), and some VPN clients don’t properly filter outgoing UDP traffic destined for ::/0 if filters aren’t set up precisely. And the cherry on top: WebRTC. Even if you’re not on video calls, browsers may perform STUN exchanges that reveal your actual IPv6.

DNS adds another twist. When systems or browsers use encrypted DNS, like DoH or DoQ, they might send AAAA queries bypassing VPN settings or the system resolver. The DNS reply gives the browser an IPv6 address, leading to a direct connection. This isn’t magic—it's about transport priority. Plus, UWP and PWA apps sometimes have their own network stacks that don’t fully follow global VPN policies. The result? You think everything’s tunneled, but some packets slip through.

Why Leaks Matter: De-Anonymization, Geo-Location, Tracking, and Blocks

IPv6 leaks are concerning for several reasons. First, they instantly tie your actions to your ISP’s address space—which reveals your geography, legal jurisdiction, and potential logs. Second, trackers and ad networks are savvy: if they see a consistent IPv6, they reliably link sessions and devices, even if the VPN changes your IPv4. Third, corporate or government blocks sometimes target IPv6 specifically—causing you to get fully blocked despite expecting protection.

Finally, there’s a structural problem with NAT. IPv4 NAT hides you behind shared addresses, but IPv6 was designed without NAT. Many home networks get a /56 or /64 prefix, and each device has a globally routable address. Sure, there are temporary addresses and RFC-level privacy, but if traffic bypasses your VPN, your real global ID shines through. It’s not catastrophic, but it’s a draft you need to close immediately.

Block or Tunnel IPv6: Choosing Your Strategy

Two Paths: Disable IPv6 or Tunnel It Through VPN

There are two basic ways to fight leaks. The first, simplest method is to completely disable IPv6 on interfaces or the kernel and allow only IPv4 traffic through the VPN. It’s reliable, quick, and repeatable. The downsides are clear: some sites and mobile networks in 2026 expect IPv6 and occasionally degrade without it, and some apps insist on QUIC over IPv6. The second, more elegant approach is full IPv6 support inside the tunnel. You get an IPv6 from the VPN provider, ::/0 routes within the tunnel, and strict firewall rules outside.

Which to pick? If you want to eliminate risk on desktop without losing functionality, temporarily disable IPv6. If you want maximum compatibility, it’s smarter to make your VPN carry both IPv4 and IPv6. This is trickier and needs provider support, but future services and networks won’t catch you off guard and scrambling to fix routing. Just remember: half-measures like "blocking a couple of prefixes" give a false sense of security.

Technical Methods: Firewall, Policy Routing, and Blackhole

If you’re blocking IPv6 locally, several solid methods exist. The most basic is disabling the stack at the system level. Next, use a firewall to strictly drop all outgoing inet6 packets on physical interfaces except the VPN. Third, add a default route ::/0 to a blackhole—so any IPv6 packet goes nowhere if no active tunnel exists. Some apply policy-based routing: tagging packets and routing only those through the VPN interface, dropping the rest.

If tunneling IPv6, apply mirrored rules. Add ::/0 routes on the tunnel interface, get an IPv6 from the VPN provider, and firewall any outgoing inet6 outside that interface. In WireGuard, this uses AllowedIPs like 0.0.0.0/0, ::/0 and a killswitch rule. For OpenVPN, enable tun-ipv6 and redirect-gateway ipv6. Don’t forget DNS: resolvers must supply AAAA records and send DNS queries through the tunnel, or traffic sneaks out again.

Performance and Overhead

Speed-wise, solid IPv6 blocking costs almost nothing, especially if done at kernel and routing table levels. IPv6 tunneling adds roughly the same overhead as IPv4—typically 3-7% CPU for encryption and processing, sometimes more on older ARM chips. In 2026, WireGuard on desktops and routers with offload runs lightning fast, so talk of “lost speed” is usually more emotional than technical.

A caveat is connection setup time. If your client misconfigures Happy Eyeballs, it may attempt IPv6 outside the tunnel and wait for timeouts while the firewall drops packets—causing sites to load a couple of seconds slower. The fix is simple: route ::/0 correctly through the tunnel or blackhole, don’t rely on a lone blocking rule inside an app. Then connections either succeed properly or fail outright—no hanging.

Windows 10, 11, and 12: Practical IPv6 Leak Protection

Quick IPv6 Disable: GUI and PowerShell

On Windows, you can disable IPv6 in two ways. The most user-friendly: go to Network & Internet, Change adapter options, select your interface properties, and uncheck Internet Protocol Version 6. It works but sometimes misses tunnel and virtual adapters. The more reliable method is the DisabledComponents registry flag; however, in 2026, Microsoft advises caution. It's cleaner to use PowerShell and netsh to avoid half-measures.

Quick commands: Run PowerShell as admin: Disable-NetAdapterBinding -Name "Ethernet" -ComponentID ms_tcpip6. Repeat for Wi-Fi. System-wide: netsh interface ipv6 set teredo disabled, netsh interface ipv6 set privacy state=enabled. For radical disabling: Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters" -Name DisabledComponents -Type DWord -Value 0xff. After reboot, IPv6 is fully off. But don’t overdo it—if your VPN supports IPv6, better configure routes and firewalls.

Filtering with Windows Defender Firewall and WFP

To avoid relying on checkboxes, create strict firewall rules. Windows Defender Firewall can block outgoing TCP and UDP over IPv6 for Private and Public profiles on all interfaces except your VPN. This isn’t obvious in the GUI, but via netsh: netsh advfirewall firewall add rule name="Block IPv6 out" dir=out action=block protocol=any profile=any interfacetype=any remoteip=any localip=any edge=yes. Then add an allow rule for the VPN interface with ::/0 addresses. Apply deny rules first, then allow rules for the VPN interface.

For pinpoint control, use WFP policies via specialized clients or group policies. They filter at the callout driver level, blocking IPv6 before packets leave the stack. For WireGuard, ensure AllowedIPs includes ::/0 and the killswitch option is enabled. For OpenVPN, use tun-ipv6 and redirect-gateway ipv6. If your provider doesn’t support IPv6, add block-ipv6 to the config.

DNS and Always-on VPN Modes

DNS often trips things up. Windows 11 has system-wide DoH, and some 2025-2026 builds test DoQ. Ensure encrypted DNS is routed through the VPN. Check the Encrypted DNS setting in network options; choose a provider from the list or let it operate "Automatically via current network" if your VPN client sets its own resolver. Otherwise, AAAA queries bypass the tunnel, exposing direct IPv6.

Another important practice: the Always-on VPN mode. Achievable in Windows through client settings or corporate MDM policies. Always enable kill switch. Without it, when reconnecting or waking, the system instantly reverts to direct IPv6, leaking a few queries. It’s like leaving a window open in winter—your home is warm but still feels drafty.

macOS and iOS: Handling PF and Profiles with Care

Disabling IPv6 and Choosing the Interface

macOS handles networks carefully but defaults to IPv6 enabled. Basic step: run networksetup -setv6off Wi-Fi, repeat for Ethernet. This disables IPv6 per service without breaking the entire stack. To re-enable, use -setv6automatic. On iOS, there’s no direct “disable IPv6” button; the system decides automatically. So, if you want a rock-solid guarantee, go the IPv6 tunneling route inside the VPN adapter instead of trying to block everything at the OS level.

If your VPN provider supports IPv6, ensure the utun interface gets an address from their pool and has a ::/0 route. Many WireGuard clients on macOS and iOS since 2025 properly set AllowedIPs ::/0 and respect killswitch. Don’t forget service priority: networksetup -listnetworkserviceorder shows the order. Put VPN above Wi-Fi and Ethernet to prevent the system from “being clever.”

PF: Simple Drop Rules for IPv6

For strict control, enable PF. Add lines like block out on en0 inet6 all and block out on en1 inet6 all in /etc/pf.conf, while allowing pass out on utun0 inet6 from any to any. Reload rules carefully: sudo pfctl -f /etc/pf.conf and enable PF: sudo pfctl -e. This ensures IPv6 won’t leak outside the tunnel. It’s a practical compromise on desktop—you don’t break the whole stack but build a solid door where it counts.

Remember macOS loves Apple services: iCloud Private Relay, Handoff, AirDrop. Private Relay may use its own traffic encryption. If you want full control, disable it first; otherwise, troubleshooting leaks gets trickier. Achieve stable VPN behavior first, then re-enable extras and test again.

DNS and Encryption: DoH, DoQ, and Resolvers

In 2026, Safari and macOS support encrypted DNS. This means your resolver might use DoH or DoQ directly if indicated by configuration profiles. When using corporate or custom profiles, verify which resolvers apply per network service. If DoH runs on Wi-Fi and your VPN doesn’t intercept it, you’ll see AAAA queries outside the tunnel again.

The rule is simple: the resolver must live inside the tunnel. Either you explicitly drop DNS queries outside the VPN interface or configure your client to publish a system resolver that Safari uses. Yes, it sounds tedious, but once you catch a subtle leak creeping in during sleep mode, you’ll understand why DNS deserves such attention.

Linux: sysctl, nftables, and Smart WireGuard

Global and Selective IPv6 Disable

On Linux, the most straightforward way is sysctl. Create /etc/sysctl.d/99-noipv6.conf with net.ipv6.conf.all.disable_ipv6=1 and net.ipv6.conf.default.disable_ipv6=1, then apply with sysctl -p. This disables IPv6 everywhere. For finer control, disable only physical interfaces: net.ipv6.conf.eth0.disable_ipv6=1, leaving tun0 or wg0 active. That way, your tunnel stack works, but outside interfaces don’t leak. Sometimes kernel parameter ipv6.disable=1 in GRUB is used as a sledgehammer—great for servers but not always ideal on laptops.

For tight control, add a blackhole route: ip -6 route add blackhole ::/0 metric 1000. It blocks any outbound IPv6 unless a higher priority tunnel route exists. This is cleaner than relying on a single firewall rule and meshes well with policy routing. Using NetworkManager? Remember to preserve route metrics and disable auto IPv6 on physical interfaces.

nftables: Ironclad Rules

nftables lets you concisely and strictly seal leaks. For example: table inet filter { chain output { type filter hook output priority 0; policy accept; oifname "wg0" accept; ip6 daddr ::/0 drop; } }. The logic is simple: allow all on wg0 interface, drop any IPv6 outside. Similarly, drop inputs if you don’t expect inbound. When tunneling IPv6, invert policy—default drop, allow IPv4 and IPv6 on wg0, and add conntrack stateful inspection to preserve return traffic.

WireGuard remains king of speed in 2026. In your client config, set AllowedIPs = 0.0.0.0/0, ::/0 for a full tunnel. Add Table = off and PolicyRouting if you want manual route control. Always enable PersistentKeepalive, especially on IPv6-only mobile networks with NAT64, to keep the tunnel alive. Don’t forget oifname rules in nftables—that’s your kill switch. Using OpenVPN? Check tun-ipv6, redirect-gateway ipv6, route-nopull, and selective push for custom routes.

DNS: systemd-resolved, resolvconf, and DoH Proxies

Modern distros mostly use systemd-resolved. Confirm your wg0 interface registers DNS via resolvectl dns wg0 10.8.0.1 with appropriate domain modes. It’s wise to disable automagic DNS on physical interfaces by setting ignore-auto-dns yes in NetworkManager and configuring resolvers manually. Otherwise, AAAA queries might leak to your ISP’s DNS, exposing direct IPv6 to browsers.

Want encrypted DNS? Run a local DoH or DoQ proxy inside the tunnel—such as cloudflared, dnsproxy, dnscrypt-proxy. Make sure upstream queries go through wg0, or they’ll bypass your protection. Quick test: curl -6 https://your-DNS-provider-address should use wg0, and tcpdump -i eth0 must show no packets on ports 853 or 443 heading to DNS hosts.

Android: IPv6-only Networks and Always-on VPN

Always-on VPN and Full Tunneling

Android has comfortably operated in IPv6-only operator networks for years. Without the right VPN, your traffic will escape via IPv6 through NAT64—exactly where leaks happen. Enable Always-on VPN with "Block connections without VPN" enabled. This built-in kill switch cuts all traffic if the tunnel drops. WireGuard’s Android client supports AllowedIPs ::/0 and 0.0.0.0/0, so run it as a full tunnel, not split.

Some apps prefer their own DNS or QUIC channels, so ensure your VPN client blocks local LAN and filters IPv6. Android 13-15 have private DNS enabled everywhere. Set it to an address only accessible through the tunnel, or choose Automatic if your VPN publishes its own resolver. Otherwise, AAAA queries reach public resolvers directly over mobile networks, destroying privacy instantly.

ADB, OEM, and Extra Tricks

You can’t disable IPv6 via the standard Android interface. Theoretically, ADB commands and sysctl tweaks on rooted devices can set net.ipv6.conf.all.disable_ipv6=1, but in 2026 that’s rare. It’s easier to ensure a proper IPv6 tunnel with strict client rules. Some OEM firmwares add network optimizations that delay traffic until the VPN is established—that’s why Always-on and blocking non-VPN connections are must-haves.

Check WebRTC on mobile browsers. Disable mDNS and direct candidates in browser settings if possible, or use extensions where supported. These small steps remove another source of your exposed IPv6 address. Always test both Wi-Fi and LTE or 5G. We’ve seen it many times: clean at home, but as soon as you’re outside, leaks show up on mobile networks.

Private DNS and QUIC

Android favors speed and enables QUIC wherever possible, especially in Google services and messengers. If your firewall or VPN client doesn’t monitor UDP, leaks slip through quietly. Configure your client to block outgoing UDP outside the tunnel except local DNS inside VPN. For Private DNS, use a domain name resolvable only through the tunnel, preventing escape attempts. Yes, a bit fiddly, but very worth it.

Routers: OpenWrt, MikroTik, and Ubiquiti

OpenWrt: RA, DHCPv6, and Policy Routing

On OpenWrt, leaks often start with RA and DHCPv6 announcements. If you want to block IPv6 outside, disable RA on LAN, forbid prefixes from the provider, and drop ip6 in the firewall. That’s straightforward. Better yet: configure your VPN to handle both IPv4 and IPv6, distributing addresses to clients via DHCPv6-PD from the VPN pool. Then browsers won’t guess routes and Happy Eyeballs works for you, not against.

For policy routing, install policy-based routing packages, mark LAN traffic, and route exclusively through the VPN interface. Add a blackhole ::/0 in the main table to stop traffic without VPN. For WireGuard on OpenWrt, set AllowedIPs ::/0 and option route_allowed_ips 1. Leave detailed comments in firewall configs—your future self will thank you. Documentation inside configs is your best friend.

MikroTik RouterOS v7: Fine IPv6 Tuning

MikroTik has its own IPv6 stack. Previously, removing the ipv6 package was common, but in RouterOS v7 it’s overkill. Set firewall rules: chain=forward family=ipv6 action=drop, except for your WireGuard or IPsec interfaces. Set ::/0 routes via VPN with higher metric for external paths. Use mangle to mark outgoing LAN packets and route them through a policy routing table with VPN-only routes.

Don’t forget ND and RA. Disable LAN announcements unless issuing VPN-provided addresses. If you do issue, confirm the prefix comes from the VPN provider and is correctly announced. Usually, this suffices to make “leak” a non-issue. Also, use fasttrack carefully; it can bypass rules if WireGuard interfaces aren’t exempted.

Ubiquiti: EdgeRouter and UniFi

EdgeRouter follows the same logic: configure IPv6 firewall rules to block outbound WAN traffic, allow tunnel traffic. Set a ::/0 route using the VPN interface. On UniFi UX, add rules per network and clients. Check how the controller manages DNS—external resolvers might be assigned to clients. Replace them with internal VPN addresses or run a local resolver that queries upstream via the tunnel.

Test guest Wi-Fi strictly. Guest isolation and separate DNS settings can bypass your global policies. One forgotten checkbox, and guest phones happily expose their IPv6 outside your secure VPN. Don’t let chance outsmart your system.

Testing: How to Confirm There Are No Leaks

Browser Checks: Addresses, WebRTC, and Tools

Start simple. Search for IP check websites and verify the visible IPs: VPN IPv4 and no direct IPv6. Use developer tools to inspect network logs. If you see AAAA queries to resolvers outside the tunnel, you have a problem. Test WebRTC with dedicated pages to reveal local and global candidates. If global IPv6 matches your ISP’s, your setup is incomplete.

Disable browser DoH auto-switch unless it's routed through VPN. In Chrome, Secure DNS must point to tunnel-accessible resolvers. In Firefox, choose system resolver or specify your own. Tedious, yes—but once you create a checklist, these steps take five minutes tops.

CLI: curl, dig, ping6, and tcpdump

The terminal gives honest answers. Run curl -4 https://example.test and curl -6 https://example.test. The IPv4 one should go through VPN; IPv6 should either use the VPN or fail if IPv6 is blocked. Run dig AAAA domain to see which resolver replies. traceroute -6 address shows if your route leaks. tcpdump -i interface ip6 uncovers any IPv6 traffic. Seeing packets on eth0 outside the tunnel means a leak—fix rules and repeat.

On Windows, use Test-NetConnection -ComputerName domain -TraceRoute -InformationLevel Detailed and start netsh trace capture. On macOS, check nettop and packet filter logs. Android is trickier without root but compare IP check screenshots across apps and monitor VPN stats. No silver bullet—look for consistent patterns for reliable results.

Automation and Alerts

If security is critical, automate checks. On Linux, run a script every five minutes curling -6 to a control host through the tunnel, verifying responses and correct interfaces. Another script monitors tcpdump on physical interfaces and sends alerts if IPv6 appears. On Windows, a PowerShell script checks ::/0 routes and firewall rules. Not rocket science—just monitoring your “dashboard lights.” They save you when someone updates drivers and resets settings.

In companies, schedule regular audits. Quarterly full scans on laptops, phones, and routers. After big updates, do accelerated tests. On routers, regularly snapshot routes and firewall rules. In browsers, verify profiles. Sounds boring but it’s like a seatbelt: inconvenient at first, lifesaving later. No exaggeration.

Cases 2024-2026: Real Practice, No Fluff

Corporate Laptop and Split Tunnel

The company allowed only business apps over VPN; everything else went direct. Logical on paper, but Teams and Zoom started using QUIC over IPv6, leaking media outside the tunnel. Partner logs saw external IPs flash. Solution: switch VPN profile to full tunnel, enable IPv6 support, add Windows Firewall rules blocking IPv6 outside the VPN, and disable forced QUIC in video clients. Result: speed stayed stable, leaks vanished, users noticed nothing.

Lesson learned. Split tunneling in 2026 demands precise cataloging of domains, protocols, and transports. If your team isn’t ready for this jungle, keep a full tunnel with proper routing. It’s dull but effective—and safer for your nerves.

ISP Home Router and Wi-Fi Phones

Common scenario: ISP provides router with RA and DHCPv6 enabled. User sets up VPN on a laptop, but phones on Wi-Fi keep using IPv6 over normal internet. Result: device behavior inconsistency and unexpected geo-targeted ads. Fix: disable RA on LAN in the router, configure OpenWrt with WireGuard distributing IPv6 from the VPN, and block ip6 entirely on guest Wi-Fi, allowing only VPN on main Wi-Fi. After this, unified policy and leaks became history.

Important: phones don’t always honor system resolvers if Private DNS is on. Therefore, configure Private DNS to a name reachable only via VPN and verify AAAA records from there. That way, you won’t need to guess who’s leaking at night.

Mobile IPv6-only Network and NAT64

An operator moved subscribers to IPv6-only with NAT64. A user enabled VPN without IPv6 support and found half the apps broken, some traffic leaking. The fix: enable IPv6 in the VPN, allow ::/0 in WireGuard, confirm resolver provides A and AAAA records, and use DNS64 inside the tunnel if needed. Bonus: activate PersistentKeepalive to keep the tunnel awake. Outcome: all services work, no leaks, and stable latency.

Takeaway: the era of "just switching off IPv6 and forgetting" is ending with mobile operators. You must embrace IPv6—but on your terms: through VPN with strict rules.

Checklists and Best Practices 2026

From Disabling to Managed IPv6

Step 1: If in panic mode, temporarily disable IPv6 on physical interfaces. Step 2: Choose a VPN provider supporting IPv6 and full tunneling. Step 3: Switch strategy—enable IPv6 inside the tunnel and block it outside. Step 4: Fix DNS—resolver only inside VPN, encryption optional but recommended. Step 5: Test with browser, CLI, and tcpdump. Finally, document everything so you don’t reinvent the wheel tomorrow.

This staircase is simple and solid. You start with a blunt off switch and end with a managed network that’s future-proof. It takes a day or two, but afterward you sleep well without chasing phantom "speed drops" or random freezes.

Choosing VPN Providers and Clients

In 2026, minimum requirements are: IPv6 tunneling, WireGuard with killswitch, proper DNS publication, forced DoH and DoQ over VPN, and advanced interface-level blocking rules. Audits and transparency policies are big pluses. If your provider says "IPv6 soon" for three years running, find another. The world has moved on—IPv6 isn’t luxury; it’s a vehicle.

Your client must: block traffic outside the tunnel, set ::/0 routes, manage priorities, show interfaces and logs that confirm traffic paths. Simple test: disable internet and watch client behavior. If the system suddenly wakes and sends packets, that client’s not good enough.

Monitoring and Regular Audits

Best practice is turning leak testing into a routine: scripts, reports, alerts. Quarterly full checks, quick tests after major updates, periodic snapshots of routes and rules on routers, profile controls in browsers. Sounds nerdy, but it’s like a seatbelt—initially annoying, ultimately lifesaving. No exaggeration.

Train users, too. A couple of slides on what a normal IP looks like in tests, how to check WebRTC, and where to report issues. Explain that private DNS without VPN isn’t privacy. People are smart—they just need the right tools.

Common Mistakes and How to Avoid Them

Disabling IPv6 Globally and Breaking Services

Hard IPv6 disable at the kernel level sometimes breaks corporate portals, new CDNs, and mobile apps. Expect this. If possible, move toward “IPv6 only inside VPN.” It preserves compatibility and stops leaks. If disabling globally, keep config backups and rollback plans. Don’t be a nighttime hero—prepare during the day.

Another mistake: forgetting the router. You disabled IPv6 on your laptop, but TVs and phones still shine global addresses over Wi-Fi. Tracking persists regardless. Implement unified policies at home or office. It’s discipline, but it pays off.

DNS Leaks from DoH and DoQ

Browsers enable DoH to public resolvers, breaking your plan. Check settings: Secure DNS must be under your control. On Windows and Android, set system providers or disable forced DoH unless tunneled. On macOS, ensure configuration profiles specify resolvers inside VPN. If not possible, deploy local DoH proxy inside the tunnel.

Another nuance: parallel resolvers. Systems may cache multiple addresses, and apps query different ones. Solution: unify on a local system resolver that accesses upstream only via VPN. This avoids chaotic mixed settings.

Issues with ::/0 Routes in WireGuard

Sometimes AllowedIPs ::/0 is set, but traffic still leaks. Check if your client used Table = off without proper policy routing setup—routes won’t apply. Also examine metric priorities: if physical interface has lower metric, system prefers it. Raise physical interface metrics or lower wg0’s. And definitely enable nftables rules dropping ip6 outside wg0—the last defense line.

We’ve also seen blackhole ::/0 added to the wrong table—command succeeded but no effect. Learn to read ip -6 rule and ip -6 route show table all. One look tells all. It’s like checking your dashboard: speed, RPM, gas—ready to go.

FAQ: Straight Answers

Do I Have to Disable IPv6 Entirely to Stop Leaks?

No. The most robust, modern approach is tunneling IPv6 inside the VPN and banning it outside. Complete disable is a quick fix if you need to patch a leak fast or your VPN provider lacks IPv6. But in 2026, growing services expect IPv6—better to embrace it than fight it.

If complexity worries you, start simple: disable IPv6 on physical interfaces, test, then enable inside the tunnel. Once confident, move toward managed IPv6. It’s evolution, not a blind jump.

How Can I Check If My IPv6 Is Leaking Now?

Two easy steps. In your browser, check if sites see your IPv6 and if it matches the VPN’s. Then, in the terminal, run curl -6 to a known site and check routing via ip -6 route get address. If packets go out a physical interface, you have a leak. Additionally, run tcpdump on the physical interface and watch for any ip6 traffic—that’s a solid indicator.

Don’t forget WebRTC. Check candidates on test pages or browser settings. If your ISP’s global IPv6 appears, the setup isn’t complete. Fix firewalls and DNS.

My VPN Provider Doesn’t Support IPv6. What Now?

Three options: temporarily disable IPv6 on devices; set strict firewall rules dropping ip6 outside the tunnel; or switch to a provider that offers IPv6 within the VPN tunnel. In 2026, IPv6 support is baseline hygiene. Living without it is tougher, especially with mobile networks and new media services.

If switching isn’t possible, keep checklists and automation—scripts that catch ip6 on physical interfaces with alerts. Let the system shout if anything goes wrong. It’s a minor compromise but real protection.

Does Blocking IPv6 Affect Speed?

If you simply drop IPv6 outside the tunnel or route it to blackhole properly, impact is minimal. Problems arise when timeouts happen: a client tries IPv6, packet is dropped, it waits before falling back to IPv4. Fix this with proper ::/0 routing through tunnel or blackhole with right metrics.

IPv6 tunneling costs about the same as IPv4, especially with WireGuard. On modern CPUs, speed differences are usually statistical noise. Stability and no "flickering" routes matter more.

Should I Disable DoH and DoQ for Security?

No need if you can route encrypted DNS through VPN. Better to encrypt than not. The issue isn’t DoH or DoQ themselves, but when they bypass the tunnel. Rule: resolvers must live inside the tunnel, and any outside-resolver attempts must be blocked. This is non-negotiable.

If immediate setup isn’t feasible, temporarily disable DoH in browsers until you confirm it only works via VPN. Then re-enable to regain privacy and order.

What About WebRTC If I Need Daily Video Calls?

Turning off WebRTC entirely isn’t practical if you rely on daily calls. The solution: configure WebRTC to only expose candidates from inside the tunnel. When IPv6 runs in VPN, it uses tunnel addresses instead of your global IP. Also, block direct local candidates if it doesn’t break features.

In corporate environments, deploy TURN servers reachable only via VPN and ensure clients can’t punch UDP holes outside. It’s stricter but prevents leaks and surprises.

Why Is Split Tunnel Problematic in 2026?

It’s not inherently bad. It requires discipline and vigilance. When half your traffic bypasses VPN, you’re juggling a puzzle of domains, protocols, and ports. Add IPv6, QUIC, and DoH, and leaks become statistically inevitable.

If your team can’t constantly update rules and monitor, better keep a full tunnel with explicit exceptions. It’s boring but reliable. In the end, results matter, not romantic rules.