If you have experienced issues connecting to Windows 2003 Servers and other Remote Desktop hosts, or connecting to Citrix sessions from Windows Vista there is a solution you may wish to try.

For an excellent post on the why's and wherefores of the issue see this post from Tom Keating. For more on the Citrix issues see this thread from the Citrix support forums.

The short answer is that the TCP Stack in Vista supports automatic receive window tuning, and this appears to result in connectivity issues in certain situations. The fix is to disable autotuning by running this command as an administrator. (Followed by a log out/log in cycle).

The following is copied directly from Tom's blog post.

- Run a command prompt (cmd.exe) as an Administrator
- Type: netsh interface tcp set global autotuninglevel=disabled
If you want to to re-enable it:
- Type: netsh interface tcp set global autotuninglevel=normal
In some cases you may need to use this command in addition to the above, but I didn't have to:
- Type: netsh interface tcp set global rss=disabled

Now be aware that this will turn off auto tuning on all connections, read Tom's article for a good explanation of how this might be prevented and the possible consequences. I can attest to the fact that it resolved a number of connectivity issues I was having.

Thanks to Mike DieBold of the Kentucky Retirement System for pointing this solution out to me!

Cheers,

Robert Porter

I have a Dell XPS M170 laptop that I love. And some time ago I upgraded it to Windows Vista Ultimate 32-Bit. It was a bit of an effort to get everything working, but for the most part I was able to find Vista drivers for everything.

However I did experience one issue. The integrated speakers worked fine, but the external headphone/speaker jack stopped working. On a lark last night, I checked Dells drivers and downloads site and lo and behold there are now new Vista ready drivers for the whole system.

I downloaded and installed them and everything is again working, including my headphones!

Lesson learned, periodically check with the hardware Vendor for new and updated drivers. It will save you some heartburn on occasion.

Scott Hanselman posted an article (see below) about what he calls the "Nuclear Option" for restoring network connectivity issues. I took the commands from his post and created a cmd file that I could run and it works well.

I knew about some of these, but not all, and I can never remember the ones I did know when I need them. So this post is as much a reminder to me as anything else.

Go see his post for more information.

Cheers,

Robert Porter

My home office network is fairly simple. DSL Modem, to a 5 port 10/100 Hub, Hub to NetGear Router, Router to 5 port 10/100 Switch, Switch to 1 laptop and 1 desktop. Other laptop connects to router via Wifi connection and I have a Vonage phone system connected directly to the router.

The hub is upstream of the router so I can connect a sniffer when needed for diagnosing chatty programs, and other traffic issues both in programs I own as well as those I write. It’s a poor-mans network tap.

Recently I have noticed some strange, albeit rare, behaviour on the switch. (I apologise for the poor quality of the picture, photography is not my strong suit.)

This picture shows the switch in normal operation, you can see that the Link, 100, and Full lights are lit for both workstations as well as the patch cable back to the router.

Every now and then I will come in and find only the Link light active. The 100 and Full Duplex lights will be off for all 3 ports. A simple reset of the switch restores full 100m connectivity. But it baffles me as to why it happens in the first place. My understanding is that the most common cause is that a network card “lost sync” and fell back to 10m half duplex operation. But since it affects all 3 ports I am guessing it is the router that is losing sync.

Anyway, a reset of just the switch suffices. Thought I would share what I have seen in case someone out there knows what the deal is, or if you are experiencing something similar at least you will know you are not alone!

If I ever come across the cause and or solution I will update this post.

Cheers,

Robert Porter

Like most geeks, I like to know as much information as possible about my environment. Over time, and with experience you begin to learn which indicators about your environment are important to you.

In this case, I am speaking about my computers’ environment. And I have determined that for me to feel comfortable about the relative health of my system there are a few key indicators that I like to keep track of.

Windows Management Instrumentation or WMI for short, is a set of API’s, functions and scripts that allow you or a program to determine real time and static indicators about your system, or your entire network for that matter. WMI has allowed me to track either summary data or drill into the depths of my system to determine what exactly is happening.

A simple example that I use daily is a Yahoo Widget called Sys Monitor. Yahoo Widgets are small, typically single purpose, programs that are run by the Yahoo Widget engine. This engine was originally called Konfabulator but renamed when Yahoo bought it. The engine is basically a JavaScript runtime engine.

The Sys Monitor, as I have it configured, displays the current system up time, CPU and Memory load, Swap file usage and size, battery charge level, Wireless signal strength and SSID connected too, as well as the IP address both local and external. And hard drive size information as well as used vs. free.

These metrics are the ones of most interest to me. But the widget can display a number of others as well.

I use a number of other Widgets, but this particular one I use all the time, it’s small and sits quietly on the desktop so that I can tell at a glance how I am doing. It has often saved me from trying to download or copy files to a drive that was almost full, and has warned me when something was eating physical memory, or hogging the CPU.

Recommended.

Cheers,

Robert Porter

As you may recall in a previous blog post I mentioned I had changed from a Linksys to a Netgear router following a failure.

Well one of the un-looked for benefits of doing so was that the Netgear router appears to do a better job of handling data. I also recently upgraded my DSL to the fastest non business option that Bellsouth offered. This is their FastAccess DSL Xtreme 6.0 which is still anemic when compared to Europe and Asia but pretty fast for the US. Connected directly to the DSL modem I ran several speed tests.

The advertised speed for my brand of DSL was 6.0 Mbps down and 512 Kbps up. With the computer directly attached to the modem I was able to achieve these speeds.

I then bridged the modem and added the Linksys router to the equation. The best I was able to achieve then was 4.5 Mbps down and 380 Kbps up. The router overhead was significant.

On a whim I decided to re-run the speed tests now that I have the Netgear router in place.

This was amazing! After running the tests a number of times it is apparent that the Netgear router does not add as much “overhead” as the Linksys router. Now this is all very unscientific, I did not track the time of day, or day of week I ran the previous tests, and to be fair I should have run a number of tests over a longer period of time and from multiple locations etc. However, it is encouraging!

I know that the Linksys routers firmware source code is available, I wonder if the same is true of Netgear? And if so I wonder has anyone made any comparisons in efficiency and overall ability between the two?

Cheers,

Robert Porter

I have gone through 3 Linksys Wireless Routers in under 2 years. All were some variant of the WRTG54G. I tried numerous firmware versions including 3rd party firmware with the first 2, the last one I left vanilla other than one upgrade just after purchase to the latest available firmware from Linksys’s web site.

The first 2 turned into semi bricks. Meaning lights were on but no one was home. The first one allowed wireless connections, but no longer allowed wired connections, even though the link lights showed normal for connected ports on the front panel. I reset, repowered, and reflashed the first one, all without error, all without success.

The second one lost the wan port. After the second one I began to suspect power transients or possible spikes on the network itself. However I placed a small hub between the router and the modem (for network sniffing) and it had no issues, nor did the DSL modem. The router is powered by a DC transformer, I checked for voltage levels and they were where they should be etc.

The third one lost the wireless lan, computers could see the AP, and sometimes even connect, but they never remained connected longer than 10 seconds, and the dang thing would never connect more than once. I tried 3 different computers and my PPC phone that has Wifi, all to no avail.

So this time I bought a Netgear Wireless router. I have used Linksys since their very first broadband router came out, but after going through 3 routers in less than 2 years I decided it might be time for a change. I have had numerous clients that used both Linksys and Netgear (as well as other brands), and could not remember hearing of any difficulties with Netgear, so I plunked down 39.99 for a brand new Wireless G 4 port router.

Installation was straight forward, I connected the router directly to my laptop, ignored the insert CD first warnings, and fired up IE. Got to the setup screens, configured the router for my PPoE connection and let it suck down the DNS and static IP from my ISP. (Bellsouth recently offered me a static IP address for no charge!).

Blamo, everything was up and running, I reconfigured the wireless settings, changed the SSID, and setup WPA security, also changed the admin password etc. All my wireless clients connected no problem, on the same channel (6) that the Linksys had been running.

We shall see what happens now, but so far the Netgear had performed flawlessly. One thing I did notice, the DDNS offerings on Netgear do not include TZO, so I downloaded and setup the software client to run as a service on one of my desktops so not a show stopper but I wonder why it was not an option?

Hmmm