In short: If your VPN is connected but you have no internet, one of eight causes is almost always to blame: kill switch triggered (intentional traffic block), DNS not resolving, MTU mismatch (pages hang half-loaded), split tunneling misconfigured, overloaded server or wrong protocol, conflict with antivirus or firewall, on mobile — battery optimization killing the tunnel, or a captive portal blocking access on public Wi-Fi. The fix sequence: switch server → switch protocol → check kill switch → reset DNS/network → restart the device.
Why VPN cuts internet access: quick diagnostics
VPN does not break the internet — it redirects all traffic through an encrypted tunnel, and any failure along that path cuts your access. Access depends on three things simultaneously: a stable connection to the VPN server, correct DNS resolution through the tunnel, and proper packet routing. A failure in any of these stops pages from loading even though the VPN status icon stays green.
| Symptom | Likely cause | What to check |
|---|---|---|
| No internet right after connecting | Kill switch or DNS | Reconnect, switch server |
| IP pings but no websites load | DNS not resolving | Set 1.1.1.1, flush DNS cache |
| Pages load halfway then hang | MTU mismatch | Lower MTU to 1280–1400 |
| Internet gone after VPN disconnected | Kill switch not releasing traffic | Reconnect VPN, restart device |
| Works on Wi-Fi, not on mobile data | Carrier blocking the protocol | Switch WireGuard → OpenVPN/IKEv2 |
| Slow and dropping out | Overloaded server | Switch to a less busy server |
Cause 1. Kill switch triggered
The kill switch deliberately blocks all traffic when the tunnel drops — to prevent your real IP from leaking — so "no internet" is sometimes the protection working as intended, not a malfunction. It activates automatically on any VPN disconnection: Wi-Fi drop, network change, unstable server. Until the tunnel is restored, the kill switch holds all traffic.
How to check: try reconnecting to VPN. If internet returns immediately, the kill switch was doing its job. If not, switch servers — the current one may be unreachable. For diagnosis, temporarily disable the kill switch in the app settings: if internet returns without VPN, the problem is the server connection, not your device.
Choose a stable, low-latency server to reduce how often the kill switch fires. See all features: LiMP VPN features.
Cause 2. DNS problem: sites won't load despite VPN showing connected
If IPs ping but no website loads, DNS is almost always the culprit — it is not resolving domain names through the tunnel. The symptom is unmistakable: browser shows "Server not found" but ping 1.1.1.1 succeeds. This means the network layer works but DNS queries are either not going through the tunnel, or being sent to your ISP's DNS server which ignores them when VPN is on.
What to do:
- Manually set DNS in your Wi-Fi or adapter settings: 1.1.1.1 (Cloudflare) or 9.9.9.9 (Quad9) — both work independently of the VPN tunnel and keep no logs.
- Flush your DNS cache: Windows —
ipconfig /flushdns, macOS —sudo dscacheutil -flushcache, Android — toggle Wi-Fi off and on. - Check the DNS leak protection option in your VPN app — make sure it is enabled.
To confirm the cause: run nslookup google.com 1.1.1.1 in a terminal — if a response arrives, DNS resolves via external servers, meaning the problem is DNS routing through the tunnel.
Cause 3. MTU mismatch: pages load halfway then freeze
If DNS is fine and IPs ping successfully but sites hang half-loaded, this is packet fragmentation from an oversized MTU — and lowering it (for example to 1280) usually fixes it immediately. MTU (Maximum Transmission Unit) is the largest data packet the network passes without fragmentation. Standard MTU is 1500 bytes; VPN adds headers (~40–80 bytes depending on protocol), pushing packets above the limit and causing fragmentation and packet loss mid-page.
Signs: large sites freeze while small text-only pages load normally; ping -l 1400 8.8.8.8 (Windows) fails with a fragmentation error.
Fix: set MTU manually in your VPN client or adapter settings:
- WireGuard: try 1280 (minimum safe for IPv6) or 1360.
- OpenVPN/IKEv2: start at 1300–1400 and increment until stable.
- Windows (PowerShell):
netsh interface ipv4 set subinterface "Wi-Fi" mtu=1300 store=persistent.
Cause 4. Split tunneling misconfigured
If only some apps lose internet when VPN is on, check split tunneling — the affected app may have ended up in the wrong list. Split tunneling routes only selected apps through the VPN tunnel and lets others go direct. If an app landed in the "bypass" list, its traffic goes around the tunnel, and with certain kill switch settings this gets blocked entirely.
How to check: open split tunneling settings in your VPN app and verify:
- The problem app is not excluded when using "selected apps only through VPN" mode;
- The app is not listed under "bypass VPN" in "all apps except selected" mode;
- Full-tunnel mode is enabled if you need complete protection.
Cause 5. Overloaded server or wrong protocol
The very first step when you see "no internet with VPN" should be switching server and protocol — an overloaded node or an incompatible protocol is the most common and most easily fixed cause. An overloaded VPN server establishes the connection (status icon turns green) but fails to route data through the tunnel.
What to do:
- Switch server. Pick another server in the same or nearby region, preferably one showing low load.
- Switch protocol. WireGuard is fastest and most stable on most networks. OpenVPN TCP is slower but passes through restrictive networks. IKEv2 handles mobile network switches (Wi-Fi ↔ cellular) particularly well.
- If your current protocol fails on mobile data, try OpenVPN TCP port 443 — the HTTPS port is rarely blocked by carriers.
Cause 6. Conflict with antivirus, firewall, or second VPN
Running two VPNs at once, an aggressive firewall, or an antivirus "network shield" breaks the tunnel — keep one tool active and temporarily disable the others for diagnosis. Antivirus suites (especially Kaspersky, ESET, Bitdefender) often include their own network filter that competes with the VPN client for control of the network interface. Two VPN clients create a routing conflict: both try to redirect traffic and block each other.
Diagnostic steps:
- Temporarily disable the "Network Shield" or "Firewall" component of your antivirus (not the whole antivirus, just the network layer).
- Ensure only one VPN client is running — close all others.
- Check Windows/macOS firewall rules: confirm the VPN app is not blocked in outbound connections.
- On corporate devices: notify your IT admin — a corporate firewall may be blocking VPN ports.
Cause 7. On mobile: battery optimization and mobile data
Mobile operating systems add two specific causes on top of the standard ones: aggressive battery saving kills the background VPN process, and carrier restrictions prevent the tunnel from establishing on mobile data.
Android: battery optimization
On Android (especially Samsung One UI, Xiaomi MIUI/HyperOS, Huawei EMUI) the system aggressively terminates background apps to save battery. If the VPN client gets optimized away, the tunnel drops automatically a few minutes after the screen turns off — internet disappears even though the app shows "connected".
Fix for Android:
- Settings → Apps → [VPN app] → Battery → Unrestricted (or "Allow background activity").
- Enable Autostart for the VPN app on Xiaomi/MIUI.
- Exclude the VPN app from Adaptive Battery or "Sleeping apps" in Android settings.
iPhone: permissions and cellular data
On iPhone check two things: cellular data permission for the VPN app, and whether the VPN profile is still valid.
- Settings → [VPN app] → Cellular Data — make sure the toggle is on.
- If you set up VPN manually (IKEv2): Settings → General → VPN & Device Management — delete the old profile and reinstall it.
- After an iOS update, VPN configurations sometimes need reinstalling — iOS updates can silently reset profile settings.
Cause 8. Public Wi-Fi: captive portal and wrong device clock
At a hotel, airport, or cafe, internet won't work until you complete the network login page (captive portal) — and a VPN turned on before that step blocks the login redirect, making it look like "no internet". Public Wi-Fi networks require browser-based authentication before granting access. If VPN is active before this step, the tunnel blocks the redirect to the login page.
Fix: connect to Wi-Fi with VPN off, complete the captive portal login, then enable VPN. Another hidden cause in public networks is a device clock out of sync: VPN uses TLS, and TLS handshakes verify certificate validity against the system clock. A device with the wrong time cannot complete a secure connection. Check: Settings → Date & Time → Set Automatically.
Step-by-step plan: restore internet in 5 minutes
Follow this sequence — most issues resolve at step one or two:
- Switch to another server — pick the nearest or least loaded one. This fixes ~60% of cases.
- Change protocol — try WireGuard ↔ OpenVPN ↔ IKEv2. On mobile, try OpenVPN TCP 443.
- Check kill switch and split tunneling — temporarily disable the kill switch and reset split tunneling to defaults.
- Reset DNS and network settings — set 1.1.1.1 manually, flush DNS, or toggle Wi-Fi off and on.
- Restart device or reinstall VPN configuration — a full reboot clears cached network state.
If none of these work and the VPN won't connect at all (not just no internet), the problem is different. More features and server options: LiMP VPN features. Plans: pricing page.
How to prevent this from happening again
Most "no internet with VPN" problems are eliminated by correct upfront settings.
- Set up auto-connect to a reliable server — favourite two or three low-latency servers. The app will failover to a backup when the primary is unreachable.
- Enable DNS leak protection in VPN app settings — this prevents DNS queries from escaping the tunnel.
- Keep the app updated — new versions fix routing and compatibility bugs for current iOS/Android/Windows.
- Disable competing VPN clients and third-party network filters — one tool at a time.
- On mobile — remove battery optimization restrictions for the VPN app once, and the problem disappears permanently.
Learn what a stable VPN infrastructure looks like: LiMP VPN features. Plans and pricing: pricing page.