My problem began with an upgrade from server 2008R1 to 2008R2. This was done back in the first part of 2012 when Serer 200 R2 had just been released. Once all the other issues were resolved one still remained which to this day no one has been able to come up with a solution to. I have heard many work-arounds but none of them is practical and in the end I am still left with the question of why it happens at all.
One the server 2008R2 system there is a folder called “Docs” which is shared as the "M:" drive to every system that uses it. Most of these are Windows 7 Home Premium. We have tried it with every possible problem-program disabled. No AV. No firewall. We did this on both the server as well as the workstations as a test. None of it mattered. After several months of off and on testing here is the most specific scenario I can give.
Maybe 90 % of the systems that need access to “M” can get it all the time. The other 10% CAN get access but ONLY if they go to the extremes of using a cellular modem/router. On a laptop running Windows 7 home Premium that is connected to the internet over (XXXXX) Cable using a brand new Linksys router, I am unable to map the drive letter. I can ping the server and it even has a low latency 100% return but NO MAPPING. If the owner of the laptop disconnected their wired connection t to the Linksys and connects it to the cellphone using it as a tethered connection for internet, the drive will map on the first try and stays mapped unless the go back to the other router.
The obvious conclusion here is that there is something being blocked by (XXXXXXX) cable service that is not blocked by their cellphone provider but I am at a total loss as to what. I have even tried other laptops and systems connected to the same setup and they fail as well
FACTS:
The brand of router used with the cable service doesn’t matter, we have tried several, They all fail
It isn't cable service in general as several other people have no problem mapping the same drive.
In one case, the problem occurs whether they are at their home in Florida in Maine (Though coincidentally BOTH use the same cable provider)
The had the provider try a full business connection to their house but that did not help. Same exact problem.
In every case the VPN to the server always connects no matter what they use. But after the VPN connects, mapping a drive is not possible.
20 other people have NO problem connecting to the same mapped drive folder on various internet connections, various versions of Windows, various AVs
We DO have 2 other people with the same exact same problem but I can find no commonality other than they also have cable that won’t work and cell service that will. (I will add that their cable is an unusual situation where a commercial “booster” was used to supply an entire condo complex a the end of a cable line that did not have enough strength otherwise. Their service is provided in “bulk” to the condo and resold to the owners
And lastly, he subnet for the office is totally different from that of their house.
At this point, as odd as it may sound, I can only think of one possibility which would be related to SMB protocols on R2 needing access to a port or ports that were not needed by server 2003 or 2008 R1 and that for some reason this port or ports are not passed through by some internet providers.
I have asked this question on other forums only to have my entry removed as being too "specific". I was under the impression that the Internet was a place where people with more knowledge could share that with those of us who lack it. I tried to include every fact that I thought might be relevant to a solution as I am only concerned with getting the system to work as it should. I know if I could help someone else with a situation like this I would feel it my duty to do so.
Any pointers would be appreciated. At this juncture I am ready to go back to Server 2003 as it was all we really needed for an OS and it worked fine.
If anyone has any idea involving port blocking or interference I really believe this is involved in some way but I have not found a way to prove it. I know that with SMB in R2