WSUS Clients Not Reporting

We are an IT company that manages multiple customer networks. We have WSUS 3.0 installed on a new Dell server with Windows Server 2008 Standard x64 edition, plenty of memory, plenty of disk space, etc. We want to be able to monitor and update our clients' computers across the internet back to our 1 single WSUS server so that we can manage their Windows Updates and patch accordingly. These customers are not on a VPN with us and we have no plans to do so. We also do not want to implement a separate WSUS server at each customer site. We have been told that it is possible by our RMM platform vendor. We have also read many posts across the internet stating it isn't possible and sometimes their seems to be a glimmer of hope that it is possible.

All of our internal computers on our network are reporting correctly to this same WSUS server on our domain. Therefore, I know we have the WSUS server setup correctly. We have implemented a separate Group Policy on our network, as well as our customers' networks with an almost identical separate Group Policy (FQDN vs. Internal). The path to our WSUS server is a FQDN without the /selfupdate and it is using the normal 8530 port. Yes, the firewall port is open and port forwarding correctly to our internal WSUS server (8530-8531 TCP, no UDP). The server also has its firewall opened correctly on port 8530, not 8531. We have turned the Windows firewall on and off to troubleshoot.

WSUS 3.0 with SP1
Client Targeting is Enabled with Group Names

We have installed and ran the WSUS Client Diagnostic Tool on two different customer networks and we are getting mixed results. Client A comes back with 100% clean and connectivity, yet, it will not show up in our WSUS server. See the output from the WSUS Client Diagnostic Tool below:


Client A comes back with:
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WSUS Client Diagnostics Tool

Checking Machine State
        Checking for admin rights to run tool . . . . . . . . . PASS
        Automatic Updates Service is running. . . . . . . . . . PASS
        Background Intelligent Transfer Service is running. . . PASS
        Wuaueng.dll version 7.2.6001.788. . . . . . . . . . . . PASS
                This version is WSUS 2.0

Checking AU Settings
        AU Option is 4: Scheduled Install . . . . . . . . . . . PASS
                Option is from Policy settings

Checking Proxy Configuration
        Checking for winhttp local machine Proxy settings . . . PASS
                Winhttp local machine access type
                        <Direct Connection>
                Winhttp local machine Proxy. . . . . . . . . .  NONE
                Winhttp local machine ProxyBypass. . . . . . .  NONE
        Checking User IE Proxy settings . . . . . . . . . . . . PASS
                User IE Proxy. . . . . . . . . . . . . . . . .  NONE
                User IE ProxyByPass. . . . . . . . . . . . . .  NONE
                User IE AutoConfig URL Proxy . . . . . . . . .  NONE
                User IE AutoDetect
                AutoDetect not in use

Checking Connection to WSUS/SUS Server
                WUServer = http://updates.<domain>.net:8530
                WUStatusServer = http://updates.<domain>.net:8530
        UseWuServer is enabled. . . . . . . . . . . . . . . . . PASS
                Client is pointed to SUS 1.0 Server
        Connection to server. . . . . . . . . . . . . . . . . . PASS
        SelfUpdate folder is present. . . . . . . . . . . . . . PASS

Press Enter to Complete
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Client B comes back with:
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Checking Proxy Configuration
        Checking for winhttp local machine Proxy settings . . . PASS
                Winhttp local machine access type
                        <Direct Connection>
                Winhttp local machine Proxy. . . . . . . . . .  NONE
                Winhttp local machine ProxyBypass. . . . . . .  NONE
        Checking User IE Proxy settings . . . . . . . . . . . . PASS
                User IE Proxy. . . . . . . . . . . . . . . . .  NONE
                User IE ProxyByPass. . . . . . . . . . . . . .  NONE
                User IE AutoConfig URL Proxy . . . . . . . . .  NONE
                User IE AutoDetect
                AutoDetect not in use

Checking Connection to WSUS/SUS Server
                WUServer = http://updates.<domain>.net:8530
                WUStatusServer = http://updates.<domain>.net:8530
        UseWuServer is enabled. . . . . . . . . . . . . . . . . PASS
                Client is pointed to SUS 1.0 Server

WinHttpDownloadFileToMemory(szURLDest, NULL, 0, NULL, NULL, NULL, &downloadBuffe
r) failed with hr=0x80190193

No Error description could be found

Press Enter to Complete
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For client B, we considered that it may be an issue with authentication in IIS on various folders within the WSUS site by turning Unauthenticated or Integrated Windows Authentication in different combinations with no success. This may be true for Client A too. Regardless, neither show up on our WSUS server.


Any ideas? We don't care how it works (unauthenticated or authenticated, or Non-SSL or SSL). We just want it to work. Any thoughts, additional troubleshooting, or strategy assistance would be greatly appreciated.

Thanks in advance!