Threat/application/port search: Port(s) Protocol Service Details Source 3389 tcp rdp Port is IANA registered for Microsoft WBT Server, used for Windows Remote Desktop and connections. Also used by Windows Terminal Server. See also: MS Security Bulletin and. Trojans using this port:, TSPYAGENT.ADDQ This port is vulnerable to Denial of Service Attack Against Windows NT Terminal Server. A remote attacker can quickly cause a server to reach full memory utilization by creating a large number of normal TCP connections to port 3389.
Restarted and I could not connect. It did not work. So I tried putting it back to 3389 and its broken now too. I have a laptop on 8.1 also and changed it at the same time, now I have the same issues. I have tried everything I can think of. Check and even turned off the Firewall, used netstat -a and it seems to be listening on the correct port. I have one XP Pro SP1 PC here at work that just does not listen on Port 3389. Netstat-an does not show that port as listening and I cannot Telnet to the port. * The Terminal Services service is started. * No errors in the event viewer * The two Remote Access checkboxes are checked in the Remote Tab of the System Control Panel.
Individual connections will timeout, but a low bandwidth continuous attack will maintain a terminal server at maximum memory utilization and prevent new connections from a legitimate source from taking place. Legitimate new connections will fail at this point with an error of either a connection timeout, or the terminal server has ended the connection. References: A vulnerability exists in the Remote Desktop Protocol (RDP), where an attacker could send a specially crafted sequence of packets to TCP port 3389 which can result in RDP to accessing an object in memory after it has been deleted. External Resources Notes: Well Known Ports: 0 through 1023.
Registered Ports: 1024 through 49151. Dynamic/Private: 49152 through 65535. TCP ports use the Transmission Control Protocol. TCP is the most commonly used protocol on the Internet and any TCP/IP network. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and that packets will be delivered in the same order in which they were sent. Guaranteed communication/delivery is the key difference between TCP and UDP.
UDP ports use the Datagram Protocol, a communications protocol for the Internet network, transport, and session layers. Like TCP (Transmission Control Protocol), UDP is used with IP (the Internet Protocol) and makes possible the transmission of datagrams from one computer to applications on another computer, but unlike TCP, UDP is connectionless and does not guarantee reliable communication; it's up to the application that received the message to process any errors and verify correct delivery. UDP is often used with time-sensitive applications, such as audio/video streaming, where dropping some packets is preferable to waiting for delayed data. When troubleshooting unknown open ports, it is useful to find exactly what services/processes are listening to them. This can be accomplished in both Windows command prompt and Linux variants using the 'netstat -aon' command. We also recommend runnig multiple anti-virus/anti-malware scans to rule out the possibility of active malicious software. For more detailed and personalized help please use our forums.
Hi Damien, Like any other COM/DCOM application, PRC dynamic ports are required for the Remote Assistance to work properly. Here are some related articles for your reference: The Offer Remote Assistance feature may not work if you do not open DCOM Port 135 in the client firewall of a Windows Vista-based computer The default dynamic port range for TCP/IP has changed in Windows Vista and in Windows Server 2008 How to reserve a range of ephemeral ports on a computer that is running Windows Server 2003 or Windows 2000 Server Hope it helps. Hi Damien, Like any other COM/DCOM application, PRC dynamic ports are required for the Remote Assistance to work properly. Here are some related articles for your reference: The Offer Remote Assistance feature may not work if you do not open DCOM Port 135 in the client firewall of a Windows Vista-based computer The default dynamic port range for TCP/IP has changed in Windows Vista and in Windows Server 2008 How to reserve a range of ephemeral ports on a computer that is running Windows Server 2003 or Windows 2000 Server Hope it helps. This may be a late reply, but if anyone else is still interested.
I was able to make remote assistance work between a XP box and a Vista box. I use the 'Offer Remote Assistance' method isntead of messaging or email method.
On the Vista Box, these settings have to be in place: -Make sure user account (offering assistance) is administrator on host PC -Go to gpedit.msc and add authorized users to list (Administrative Templates-System-Remote Assistance-Offer Remote Assistance:Enable; add account or security group to the list of authorized accounts) -Add the following to firewall exceptions list: Network Discovery Remote Assistance Windows Remote Asistance Still trying to figure out how to remote assistance from XP to Windows 7, though.