Troubleshooting simplewall: Fixing "No Internet Connection" & Rule Errors

When activating simplewall in its default Whitelist (block all) mode, every network connection not explicitly allowed by a rule is dropped. This maximum-security model can sometimes cause your web browser or Windows system services to appear offline.

Follow this quick, verified troubleshooting checklist to restore connectivity in seconds while preserving your security shield.

Issue 1: Web Browsers Cannot Open Websites (DNS Failure)

Symptom: Browser displays DNS_PROBE_FINISHED_NO_INTERNET or ERR_NAME_NOT_RESOLVED, but pinging IP addresses like 8.8.8.8 works.

Solution: In Windows, domain names are resolved by the Windows DNS Client service (`Dnscache`), which runs under `svchost.exe`.

1. In simplewall, switch to the System Rules tab.
2. Ensure Domain Name System (DNS) outbound rule is checked.
3. Alternatively, in the Applications tab, allow svchost.exe (DNS Client).

Issue 2: No IP Assigned on Wi-Fi / Ethernet (DHCP Blocked)

Symptom: Your computer shows "No Internet, secured" or has an APIPA address (`169.254.x.x`).

Solution: Your network router requires DHCP (Dynamic Host Configuration Protocol) on UDP ports 67 and 68 to assign an IP address.

• Enable the internal rule for Dynamic Host Configuration Protocol (DHCP). This allows outbound broadcasts to your local router gateway.

Issue 3: Windows Update or Microsoft Store Not Working

Windows Update operates across multiple services (Delivery Optimization, BITS, and TrustedInstaller). To allow updates safely:

• Open simplewall > System Rules.
• Temporarily enable the Windows Update rule set when checking for security patches.
• You can keep telemetry rules active even while Windows Update is downloading patches.

Issue 4: Temporary Emergency Reset

If you ever find yourself locked out of your network completely, simplewall includes an instantaneous failsafe:

• Click the Disable filtering button on the toolbar or right-click the system tray icon and choose Disable filtering.
• This immediately flushes all temporary WFP filter handles and restores default Windows networking without restarting your PC.