In this article

If local DNS resolution is failing, a possible cause is that either EDNS isn't supported or a firewall is blocking EDNS queries.

Windows deployments

Beginning with Windows Roaming Client 1.11.0, EDNS0 was added to local domain queries for failover.

In versions 2.2.1 and older, local DNS resolution may fail if the internal DNS resolver or firewall does not support EDNS0.

This issue no longer affects Windows Roaming Client 3.0 or higher, which automatically retries local DNS queries without EDNS0 when needed.

✍️ To reenable EDNS for local domain queries for failover, set the record value to true.

Agent versions 2.2.1 and older

Use this registry setting only for legacy agents that still rely on loopback-based DNS routing.

1. Add a registry entry to disable EDNS for local domain queries for failover

   • reg add “HKLM\SOFTWARE\DNSFilter\Agent” /v IncludeLocalResolversEdnsRecords /d “false” /f

   • reg add “HKLM\SOFTWARE\DNSAgent\Agent” /v IncludeLocalResolversEdnsRecords /d “false” /f

2. Restart the device or the Roaming Client to apply the change

Agent versions 3.0 or higher

The 3.0 agent performs its own fallback logic and does not require registry changes.
If editing is necessary for loopback mode, the setting is controlled through the JSON configuration system.

Add the following to appsettings.Overrides.json:

"LoopbackProxy": {
    "IncludeLocalResolversEdnsRecords": false
}

macOS deployments

Follow these steps to resolve this issue.

1. In your device Terminal, open DNSFilter Agent daemon.conf
   a. see issue diagnostics for steps to navigate to the daemon.conf file

2. Add the following option to the top of the configuration file:

   IncludeLocalResolversEdnsRecords=false

   Before

   

   After

   

    

3. Restart the daemon

   • launchctl unload /Library/LaunchDaemons/com.dnsfilter.agent.macos.helper.plist 
     launchctl load /Library/LaunchDaemons/com.dnsfilter.agent.macos.helper.plist

   • launchctl unload /Library/LaunchDaemons/io.netalerts.agent.macos.helper.plist 
     launchctl load /Library/LaunchDaemons/io.netalerts.agent.macos.helper.plist

4. If the daemon does not restart, restart the device to push the update