# Remote Control - Knowledge base

## Unable to connect to remote computers

### Using Endpoint Central

#### Problem

Unable to establish connections to remote computers from the server.

#### Cause

The inability to connect to remote computers from the server could be because of one or more of the following reasons:

- Communication is blocked by the firewall in the computer in which the server is installed. To confirm if this is one of the reasons, try connecting to the server from a computer to which you want to establish a remote connection using Telnet. Execute the following command in the Command Prompt window:

  *telnet* <space> *Desktop_Central_Server_IP* <space> *Remote_Control_Gateway_Port*

  For example:

  ```
  telnet 192.168.110.23 8443
  ```

  If you are unable to connect, you can be sure that the firewall is blocking communication between the server and agent.

- No agent is installed in the computer to which you want to establish a remote connection.
- Unable to access the target computer.
- Issues related to browsers. For example, absence of Java plug-ins and ActiveX controls.

#### Resolution

Identify the problem and follow the relevant resolution from the list given below:

**Communication blocked by firewall**

The communication required to connect remotely to a computer could be blocked by either of the firewalls mentioned below:

**Firewall in the Server**

The firewall running in the machine in which the server is installed may block requests. To resolve this issue, add the following:

- Port 8443 to the exceptions list of the firewall.
- "Remote Assistance" to the exceptions list of the Windows firewall.

**Firewall between Server and LAN Agents**

Consider a scenario where you are managing computers in your remote offices from your head office and you use "Direct Communication" between the LAN Agents and Server. If you have a firewall between the Server and the LAN Agents, you should configure the firewall to enable remote administration:

- For Remote Administration, open the TCP port 135.
- For File and Printer Sharing, open the ports TCP 139, TCP 445, UDP 137, UDP 138.

**DC Agent is not installed**

Check if the Agent is installed in the Client Computer. If not, push and install the agent in the client machine from SoM. The steps include:

**From the UI**

1. Select the *Admin* tab to invoke the Admin page.
2. Click the *Scope of Management* link available under Global Settings. This invokes the Scope of Management page.
3. The *Computers* tab is selected by default, showing all the computers that have been added already.
4. Select the computers for which the Agent has to be installed and click *Install Agent*. Click *OK* to confirm.

**Installing Agents Manually**

You can also install the agents manually by downloading the agent program from the SoM page:

*For Local Office*

Click the **Download Agent** link and select **Local Agent (LAN)** to download the agent installable.

*For Remote Office*

Click the **Download Agent** link and select the corresponding **Remote Office** name to download the agent installable.

Double-click the MSI file to install the agent manually.

**Problems accessing the target computers**

- Check if the selected computer is down. If so, make it up and running.
- Specify and use the IP Address of the computers to connect, if you have computers with the same name in two different domains/workgroups.
- Verify whether the IP Address of the selected computer is shown correctly. In case there is a Virtual IP, you will need to remove the virtual IP Address for Remote Control. The steps would include:
  1. Select the Tools tab and go to Remote Control.
  2. Click on the Edit IP icon under the IP Address field.
  3. Remove the virtual IP address or correct the IP address in the IP Address text field.
  4. Save changes and log in afresh.
- Enable "File and Printer Sharing for Microsoft Networks" in the network adapter of the client computers. The steps are as follows:

1. Select Start --> Settings --> Network Connections.
2. Right-click the network connection and select Properties.
3. In the connection properties dialog, select the General tab.
4. Select "File and Printer Sharing for Microsoft Networks" and click OK.
5. If you do not find this option, click Install.
6. In the network component type, select Service and click Add.
7. Select **File and Printer Sharing for Microsoft Networks** and click OK.
8. Click Close to exit the properties dialog.

**Browser issues**

- Ensure your browser has Java plug-ins.
- Enable [ActiveX](https://www.manageengine.com/products/desktop-central/help/remote_desktop_sharing/remote_desktop_pre-requisites.html) Controls in Internet Explorer.

### Using Endpoint Central Cloud

#### Problem

Unable to establish connections to remote computers from the server.

#### Cause

The inability to connect to remote computers from the server could be because of one or more of the following reasons:

1. The computer may be down.
2. Computers belonging to different workgroups/domains may have the same name.
3. **File and Printer Sharing for Microsoft Networks** is not enabled.

#### Resolution

Identify the problem and follow the relevant resolution from the list given below:

1. Check if the selected computer is down. If so, switch it on.
2. Specify and use the IP Address of the computers to connect, if you have computers with the same name in two different domains/workgroups.
3. Enable **File and Printer Sharing for Microsoft Networks** in the network adapter of the client computers. The steps are as follows:
   - Select Start --> Settings --> Network Connections.
   - Right-click the network connection and select Properties.
   - In the connection properties dialog, select the General tab.
   - Select **File and Printer Sharing for Microsoft Networks** and click **OK**.
   - If you do not find this option, click the **Install** button.
   - In the network component type, select **Service** and click **Add**.
   - Select **File and Printer Sharing for Microsoft Networks** and click **OK**.
   - Click **Close** to exit the properties dialog.

**Applies to:** Remote Desktop Management, Troubleshoot Remote Desktop, Remote Desktop Connection problems

**Keywords:** Remote Desktop, Manage Remote computers, Troubleshoot Remote machines