In this article

Work around Hyper-V Internet Connection Sharing (ICS) issues when Windows Roaming Client diagnostic logs show an error about being unable to bind to port 53.

Windows Roaming Client version 1.12.0 and higher has improved compatibility on computers that also use virtualization platforms or technologies. Earlier versions conflicted with these technologies over port 53. Improvements are expected with Hyper-V, Windows Subsystem for Linux (WSL), and Docker or Windows Sandbox containers.

Cause

The Hyper-V hypervisor and its virtual machines do not conflict with the Roaming Client, but some services that Hyper-V uses can. The main cause is the ICS service, which automatically runs a DNS server on 0.0.0.0:53 (all interfaces). This prevents the Roaming Client system service from starting.

On Windows 11 and Windows 10, the issue most often occurs after waking from sleep or after a shutdown. The diagnostic logs for the Roaming Client show an error about being unable to bind to port 53.

Microsoft Defender Application Guard also uses Hyper-V to open untrusted sites in an isolated container in the Microsoft Edge browser. Microsoft has deprecated Application Guard for Microsoft Edge for Business, and it is not available starting with Windows 11, version 24H2.

Work around this issue with the following options, or consider switching to Chrome Enterprise as the primary browser for the organization.

Work around the issue

If the Roaming Client service (DNS Agent or DNSFilter Agent) starts before the ICS service, the ICS service starts with no issues. Use one of these two workarounds.

Option 1: Disable Host Network Service triggers

1. Open a command prompt as an administrator and run the following command to delete any trigger for the Host Network Service (HNS):

   sc qtriggerinfo hns delete

2. Restart the computer.

Option 2: Set HNS and ICS to manual startup type

Setting the HNS and ICS services to a manual startup type can give the Roaming Client enough time to start before them after a reboot. This avoids stopping and starting the services manually each time to get the Roaming Client to run.

1. Stop the Host Network Service (HNS). 

   HNS must be stopped before the ICS service can be stopped.

2. Stop the Internet Connection Sharing service.
3. Start the Roaming Client service.

4. Restart the Host Network Service. 

   The ICS service restarts automatically.

Related content

• Download Windows Roaming Client log files
• Windows Roaming Client configuration reference (registry and JSON)