# Agent Installation - Knowledge base

## Unable to connect to Distribution Server

### Problem

While trying to download the bootable media, the target machine can't connect to the Distribution Server installed machine.

### Causes

1. The target machine is not in the same network as the Distribution Server.
2. The HTTP/HTTPS ports are not reachable from the target machine.
3. The HTTP/HTTPS ports are blocked in the Distribution Server by a firewall or antivirus.
4. Issues while configuring the Distribution Server.

### Resolution

#### 1. Ensure that the Distribution Server is reachable from the target machine.

From the target machine, follow the steps given below:

1. Open the command prompt.
2. Execute the following command: **ping <distribution_server_IP>** where distribution_server_ip is the IP address of the machine where the Central Server is running.
3. Ensure that server is reachable using ping statistics.
4. If not, contact your network administrator.

#### 2. Check the reachability of the HTTP port and HTTPS port

1. Open the command prompt.
2. Execute the following commands:
   - telnet <DS Server IP> <http port number>
   - telnet <DS Server IP> <https port number>

   Example:
   - telnet 192.168.139.116 8021
   - telnet 192.168.139.116 8384

3. If it opens a blank command prompt, the port is reachable. If not, proceed to step 3.

##### Steps for enabling Telnet in Windows:

1. Go to Control Panel → Programs and Features.
2. Click "Turn Windows features on or off".
3. Select "Telnet client" and click OK.

#### 3. Check if Windows Defender Firewall blocks HTTP or HTTPS ports

1. Navigate to Control Panel → Windows Defender Firewall on the Distribution Server machine.
2. If the firewall is disabled, proceed with Step #4.
3. If enabled, go to Advanced Settings → Inbound Rules → New Rule.
4. Select Port, specify HTTP/HTTPS port numbers (e.g., 8021, 8384).
5. Allow the connection, name the rule, and click Finish.

#### 4. Check if Antivirus blocks communication

If you have antivirus software installed on the Distribution Server machine, ensure that its settings do not block communication with the target machine.

#### 5. Check if the Distribution Server is running with a valid IP address

1. Press Windows + R, type **services.msc**.
2. Search for **ManageEngine UEMS - Distribution Server**.
3. Ensure the status of the service is "Running". If not, start the service manually.

In the web console:

1. Navigate to the Agent page → Remote Offices.
2. Check if the IP address of the Distribution Server is valid.
3. If not, click Action → Modify → Update with a valid IP address and click Modify.

If the issue persists, contact support for further assistance.