Remote Desktop Not Working

Last Modified

Mon Sep 28 18:08 GMT 2020

Description

• This is a simple guide on troubleshooting RDP issues.

Environment

• N-able N-central

Solution

• N-able N-central 2020.1

• N-able N-central 2020.1 introduces the Custom Protocol Handler application for RDP/Remote Desktop only Operator machines running Windows and replaces the need for java on the Operator machine. The Target/Agent reaches back to N-able N-central using .NET to create the second half of the SSH or HTTPS tunnel via N-able N-central , and nothing changes. The recommended troubleshooting is:
  • Add exclusions on the Oparator Machine to AV/ISA products for the application.
    • "C:\Program Files (x86)\ N-able\Custom Protocol Handler\Remote Application Launcher.exe"
  • enable Outbound TCP port 22 to N-able N-central from the Operator AND Target devices (recommended).
  • enable Outbound TCP port 443 to N-able N-central from the Operator AND Target devices (required).
  • Allow DNS resolution of the N-able N-central Server from Operator and Target machines or environments.
  • Also see:
    • https://documentation.n-able.com/N-central/userguide/Content/Administration/NetworkSetup/Port_access_requirements.html

• Earlier versions of N-able N-central

• If Remote Desktop is not working, check the following steps:

1. Make sure Signed ActiveX Controls are not blocked.
2. Clear cache: you can clear your java cache by deleting temporary files: Control Panel > Java > Temporary Internet Files.
3. Check for local firewall devices/software, restricting port 22 from Operator machine to N-able N-central,.
4. Local DNS: consider a local dns entry or lmhosts file entry in case the Operator machine is reaching out externally from inside your network (and back again). Hopping out and back in could be the issue.
5. Add Security exception: Open the Java icon in Control Panel (Or click Start and type "Configure Java") > Click "Security" tab > Click "Edit Site List" button > Add the N-able N-central url to Exception Site list (URL should begin with http:// or https://).
6. AV product: temporarily disable AV products as a test.

• You can also check Java network settings:

1. Start Java Control Panel (from windows control panel -> java, OR from Java folder)
2. On General tab click Network settings
3. Choose Direct connection instead of Use browser settings
4. Click OK and reattempt RDP.

• Consider removing the Default.rdp application which is typically located in 'Documents' and re test Remote Desktop.