Configuring proxies for RealVNC Connect

This article explains four related error messages you may see in RealVNC Connect/RealVNC Server, all caused by a problem with the proxy server configured on this device, and how to resolve each one.

• Can't connect through your proxy - authentication error
• Can't sign in to your proxy
• Proxy requires sign-in credentials
• Can't connect through your proxy - protocol error

In every case, cloud connections will not work until the underlying proxy issue is resolved.

Can't connect through your proxy - authentication error

"The proxy this device uses requires an authentication method that RealVNC Connect/RealVNC Server doesn't support. Cloud connections won't work until a compatible proxy is configured. Switch to a proxy that uses a supported authentication method."

What this means: the configured proxy requires an authentication method that RealVNC Connect/RealVNC Server does not support. RealVNC Connect/RealVNC Server supports proxy authentication using a user name and password, configured through the Proxy section in the Settings menu.

If your proxy relies on a different authentication method that these parameters do not cover, RealVNC Connect/RealVNC Server will not be able to authenticate against it.

How to fix it:

1. Speak to your network administrator to confirm what authentication method the proxy is using.
2. Where possible, switch to, or add, a proxy configuration that accepts a user name and password for authentication.
3. Update the Proxy settings in the Settings menu
4. Restart RealVNC Connect/RealVNC Server and confirm that cloud connections are now working.

Can't sign in to your proxy

"RealVNC Connect/RealVNC Server couldn't authenticate with the configured proxy because the credentials are incorrect. Cloud connections won't work until the proxy credentials are updated. Check your proxy username and password in this device's connection settings."

What this means: a proxy user name and password have been set, but the proxy has rejected them as incorrect.

How to fix it:

1. Confirm the correct proxy user name and password with your network administrator.
2. Update the proxy username and/or password using the Proxy settings in the Settings menu.
3. Restart RealVNC Connect/RealVNC Server and confirm that cloud connections are now working.

Proxy requires sign-in credentials

"The configured proxy requires a username and password, but none have been set for RealVNC Connect/RealVNC Server. Cloud connections won't work until proxy credentials are provided. Add your proxy username and password in this device's connection settings."

What this means: the proxy is asking for a user name and password, but none have been configured for RealVNC Connect/RealVNC Server yet.

How to fix it:

1. Confirm the proxy user name and password with your network administrator.
2. Update the proxy username and/or password using the Proxy settings in the Settings menu.
3. Restart RealVNC Connect/RealVNC Server and confirm that cloud connections are now working.

Can't connect through your proxy - protocol error

"RealVNC Connect/RealVNC Server couldn't communicate with the configured proxy due to a protocol mismatch. Cloud connections won't work until the proxy configuration is corrected. Check that the proxy address and type (HTTP/SOCKS) are correct, or try a different proxy."

What this means: RealVNC Connect/RealVNC Server connected to the address given for the proxy, but what responded did not speak the protocol expected. This is usually caused by the proxy type (HTTP or SOCKS) not matching what is actually running at that address, or by an incorrect address or port.

How to fix it:

1. Confirm the correct proxy address, port, and type (HTTP or SOCKS) with your network administrator.
2. Update proxy server type using the Proxy settings in the Settings menu.
3. Restart RealVNC Connect/RealVNC Server and confirm that cloud connections are now working.

Checking your proxy configuration

Before updating RealVNC Connect/RealVNC Server's proxy settings, it can help to confirm what proxy your device is actually configured to use. Where that is checked depends on your operating system.

Windows

1. Check the proxy settings under Settings > Network & Internet > Proxy, or Internet Options, for RealVNC Connect/RealVNC Server running in User Mode.
2. If RealVNC Connect/RealVNC Server is running in Service Mode, the proxy is instead set centrally using the netsh winhttp utility, for example netsh winhttp show proxy.

macOS

1. Open System Settings, then go to Network.
2. Select your active network connection and check its proxy settings.

Linux

1. Check your standard proxy environment variables, for example http_proxy and https_proxy.
2. Alternatively, check your desktop environment's libproxy configuration if environment variables are not set.

If you cannot change the proxy

If your organization's proxy cannot be changed or replaced, consider whether an exception, or a separate egress path, can be created specifically for the domains and IP addresses RealVNC Connect uses. These are listed in Network Access Requirements.

Alternatively, if cloud connectivity is not required for your use case, you can use direct connections instead, which do not depend on RealVNC Connect's cloud service. Please note that direct connections are only available with Premium and Enterprise subscriptions.

Still need help?

If you have followed the steps above and are still unable to establish cloud connections, submit a request to our support team with details of your proxy server type, authentication method, and RealVNC Connect/RealVNC Server version.