Skip to main content

Windows Server 2008 R2 DNS issues

This week we stumbled upon some weirdness in our new 2008 R2 DNS servers. A couple of URLs, for example www.smhi.se and www.stockholm.se could not be resolved from a 2008 R2 server. The existing 2003 servers with the same configuration worked perfectly.

After thorough troubleshooting we found out that there is a new default setting in Windows Server 2008 R2 regarding the EDNS-protocol that caused the issues. Not all of the DNS servers around the internet are able to handle EDNS, but in 2008 R2 this protocol is enabled by default. Normally you would think there is a fallback mechanism to standard DNS protocol if an EDNS request fails, but Windows Server does not have that.

The solution was simply to disable EDNS by using the command: dnscmd /config /EnableEDNSProbes 0

Scott Forsyth has written more about this issue and how he found the solution:
http://weblogs.asp.net/owscott/archive/2009/09/15/windows-server-2008-r2-dns-issues.aspx

Comments

Popular posts from this blog

Moving to the cloud - part 1

I cannot with words describe the hype around the cloud today, and of course I had to join the croud. I have transferred all my applications, files and services to the cloud. I thought I would share some of the experiences and difficulties I have hit during my jourey. These are the steps I have performed in order to complete my move to the cloud: Most of my files are safely stored with  Dropbox . E-mail accounts for stodell.se  were moved from service provider to  Google Apps . The Cornball was moved from service provider to  Windows Azure och SQL Azure . This blog was moved from Wordpress at a service provider to  Google's Blogger . Even though  Loopia has been a great service provider during many years I have now been able to cancel all my services except the domain hosting with them. The replacement being free services and the Azure capacity that is included in the MSDN subscription.

Binding a HTML-formatted string to a WPF WebBrowser control

Sometimes there is a need to display a HTML formatted string in a WPF application. There are a couple of ways to do this, but the most stright forward is to use a WebBrowser control and the NavigateToString method. This approach has one big flaw, you cannot use binding to a string out of the box, but I found a great solution through Stack Overflow which adds a bindable property to the  WebBrowser  control using  NavigateToString . The following class is all that is needed to add that behavior. A new depencency property named Html is introduced to the  WebBrowser  and the proper change action is performed in the OnHtmlChanged method. public class BrowserBehavior { public static readonly DependencyProperty HtmlProperty = DependencyProperty.RegisterAttached( "Html", typeof(string), typeof(BrowserBehavior), new FrameworkPropertyMetadata(OnHtmlChanged)); [AttachedPropertyBrowsableForType(typeof(WebBrowser))] public static string GetHtml(WebBrowser bro

Using Bootstrap Tooltip to show Parsley validation errors

I'm currently working on a web application using a variety of different frameworks, such as Backbone for the back-end, Bootstrap for the front-end and Parsley for client side form validation.  Parsley is a really powerful validation toolkit, but it takes some tweaking to make it blend with the Bootstrap front-end. Fortunately this is a one time fix, which can be re-used all over our project. Since there will be some custom options in our  Parsley  object, we can't use the default parsley-validate attribute on the form. Instead we have to initialize the validation with the jQuery syntax: $('#my-form').parsley(parsleyOptions); The options are were the magic happens, and in our case we have a global options object that our forms use to get the same experience all over the application. Here's what it looks like: var parsleyOptions = {  // Sets success and error class to Bootstrap class names  successClass: 'has-success',  errorClass: 'has-er