You are a help desk technician for your company. A portion of your company’s network is shown in the exhibit.
Michael is an employee in your company’s marketing department. Michael uses a Windows XP Professional computer that is located on Subnet A. You use a Windows XP Professional computer that is located on Subnet B. The company’s firewall does not use Network Address Translation (NAT).Michael sends you a Remote Assistance invitation. In Windows Messenger, you accept the invitation, but you cannot connect to Michael’s computer.Next, you run the Ping command, which verifies connectivity to Michael’s computer.
You need to establish a Remote Assistance connection with Michael’s computer.
What should you do next?
A.
Ask your firewall administrator to open the TCP/IP ports that are used by Windows Messenger.
B.
Ask your firewall administrator to open the TCP/IP ports that are used by Remote Desktop Services.
C.
Instruct Michael to create an invitation file and then e-mail the file to you as a file attachment. When you receive the e-mail, open the file attachment.
D.
Instruct Michael to edit the System properties for his computer and add your domain user account to the Remote Desktop Users list on the Remote tab.
Explanation:
The problem in this scenario is that the firewall is blocking the Remote Desktop Protocol port 3389. Remote Assistance uses the Remote Desktop Protocol port 3389 for outbound RDP traffic. This port is typically blocked on most irewalls, in which case we cannot connect to the Remote Desktop. We must configure the firewall to enable Remote Desktop Services program, which is Mstsc.exe, to make outbound TCP connections on port 3389.Incorrect Answers:
A: The Windows Messenger uses port 1863 for instant messaging; ports 6891 through 6900 for file transfers; and port 1503 for Whiteboard and application sharing. Remote Desktop Services on the other hand uses port 3389 for outbound traffic. Enabling the ports used by Windows Messenger will thus not enable us to connect to the Remote Desktop.
C: E-mail can be used to send the invitation which Michael has already done. However, the firewall is preventing outbound traffic from our computer via port 3389. This port is used to create a connection to a remote desktop and should be configured to allow the Remote Desktop Services program to send outbound traffic.
D: The remote computer must be configured with a list of users that are permitted to connect remotely to the computer before the user will be able to send a Remote Assistance invitation. As an invitation has been sent, therefore our user account is on the remote Desktop Users list.