Who’s the Man Blog

At my place of business we use alot of MS Terminal Services 2003 coupled with a commercial linux distro that runs rDesktop called 2x. Alot of our ends users specifically needed to take pictures with their digital camera and upload them to the server(the camera is configured to display as a usb disk drive). This was working fairly well up until recently when all of a sudden the user would go to access the camera as a RDP redirected drive and it would wait and wait and wait about 30 seconds then show you the folder and it was the same for each click into a sub folder on the drive. We tried everything  uninstall antivirus, different service packs, different client(including a custom linux distro I built years ago with thinstation.org), no luck.

So I worked on something else for a week, to be honest I thought: Wow, what a weird issue hope somebody else has seen it and written something up. I came back to it today and thought it had to be failing out somewhere on what I assumed to be a file type access so I ran filemon utility from Microsoft.   To be honest never run this utility on a box that is in production it generates alot of crap I mean output. Sure enough within two minutes I figured out the issue, and why it came up just recently. The explorer process was trying to access a network share called \\tsclient\hotplug (this is what usb drives are redirected under from linux) and getting back a ”path not found” error. While I have seen the explorer bar read \\tsclient\C numbers of times on redirected drives I never gave it much thought. I thought it was a Microsoft cute way of integrating the RDP into the explorer. Well in a normal network this works fine the system puts a request out to DNS/hosts/WINS and fails out nearly instantly, and then some peice of code must then point the name to the server itself. Our systems were resolving tsclient to an actual IP via the DNS upstream provider we started using OPENDNS. OPENDNS has a couple of nice features our ISP doesn’t provide DNS STATS, DNS Blacklisting, Typo correction, and guided search so if a user types a incorrect web address it will try and correct or bring you to a search page with that as a search keyword. The way this works is for unresolvable names it returns the IP address of OPENDNS server and your webbrowser goes to their servers and they serve up a search page using the host header you requested. So on our terminal server when our users would click into the \\tsclient\hotplug , the system would resolve the name tsclient and it receive a IP to OPENDNS servers that would then need to failout, and then go about its normal rendering of the tsclient shares. The best solution I figured out was to create a DNS entry for “tsclient ” on our internal DNS servers and have it resolve to 127.0.0.1. This solved the speed issue instantly.

Hope this helps someone else!