Hello Jeff,
The article you posted is a good one. I remember that issue on my machines.
RDP stopped working until I applied the necessary patches from Microsoft. I
would first make sure she has all the available security updates from
Microsoft. Keep in mind that Windows 7 went end of life on January 2020, so
you'll need to make sure she got the last Service Pack that was issued as
well. If she's still on Windows 7, I doubt she gives priority to applying
updates, so it's possible this is the culprit.
After you verify that, 3 main issues I have seen that keep VPN connections
from working are as follows:
1) DNS - Fixed by using the Windows 10 internal IP address instead of the
hostname for an RDP connection on the Windows 7 machine.
2) Firewall - Fixed by reviewing the Windows 10 firewall and any network
firewalls that are in place.
3) Routing - Fixed by reviewing the routing table on the Windows 7 machine
with "route print" from the command line. If no route exists, then need to
adjust VPN settings.
Below is a longer walkthrough for the above suggestions:
Item 1
Is the RDP connection on the Windows 7 box set up with the computer hostname
or with an IP address? Hostnames typically need to be fully qualified in
order to function on outside machines. IP Addresses, although "ugly" to most
people, remove the hassle of DNS not working. The computer name in the RDP
connection should be fully qualified as:
<PC_hostname>.<your_company_domain>. Verify DNS translation is working by
using the "ping" tool from the command prompt. "ping
<computer_name_used_in_RDP>". If this fails, then DNS is failing to resolve
the Windows 10 hostname and you should just have her try connecting with RDP
using the Internal IP address of the Windows 10 machine.
Item 2
If even the Internal IP address fails to connect, check Windows Firewall on
the Windows 10 machine to make sure Inbound RDP connections are allowed on
the currently active network profile (Domain, Public, Private over TCP/UDP
port 3389. You typically need both ports. TCP is used for the initial
connection, and UDP is for the actual remote viewing and interaction). Also,
you can check to make sure that the VPN firewall rules were set up properly
to allow her VPN traffic access to her workstation subnet (typically the
LAN).
Item 3
Also, check to make sure that her VPN tunnel has a route to her Windows 10
machine. After the VPN is activated on the Windows 7 machine, open the
command prompt and perform a "route print" on the Windows 7 machine and look
for a line item that has the IP address of her Windows 10 workstation (or
the subnet that the Windows 10 machine is on). If you do not find that route
line item, then that is a problem, but may not be the only problem.
------------
Jacob
------------
-----Original Message-----
date: Mon, 17 Jan 2022 14:45:10 -0500
from: Jeff Crosby <jlcrosby@xxxxxxxxxxxxxxxx>
subject: [PCTECH] Remote desktop from Windows 7 to Windows 10
A coworker has to quarantine 2-3 days until a COVID test on her daughter
comes back. If positive, the coworker will need to quarantine for 10 days.
We are trying to have her remote in from her Windows 7 desktop at home to
her Windows 10 desktop at work. No joy, it says it cannot find the
computer. The VPN is definitely up because she can get ACS green screens
from home.
I *can* remote desktop from my Windows 10 desktop at my house to her Windows
10 office desktop, so I'm speculating it has something to do with Windows 7.
I have it set to allow any version of remote desktop. I have NLA (Network
Level Authentication) turned off.
I found this and tried it:
Fix (workaround) is below
found this
<snip>
https://support.microsoft.com/en-us/help/4103721/windows-10-update-kb4103721
Addresses an issue that may cause an error when connecting to a Remote
Desktop server. For more information, see CredSSP updates for CVE-2018-0886.
directed to here
https://support.microsoft.com/en-us/help/4093492/credssp-updates-for-cve-201
8-0886-march-13-2018
An update to change the default setting from Vulnerable to Mitigated.
the update changed
Policy path: "Computer Configuration -> Administrative Templates -> System
-> Credentials Delegation"
Setting name: "Encryption Oracle Remediation"
I enabled the local policy and set it back to Vulnerable
Both RDC and VMs via VMMSSP are working
</snip>
But that did not work for me.
Any suggestions?
Thanks.
midrange.com
