Install ASP.NET 4.0 alongside ASP.NET 2.0 on IIS6

asp.netiis-6windows-server-2003

I've read where you create a new application pool, one for 2.0 sites and one for 4.0 sites. But there is no option I see when creating a pool to configure the framework.

My problem is I have several 2.0 sites running as the Default Web Site. I added a WCF 4.0 service under a new virtual directory and set the framework to 4.0. I also put it in a separate app pool.

Now, I can only get one working at a time. Either the 2.0 sites or the 4.0 site. I get:

It is not possible to run two
different versions of ASP.NET in the
same IIS process. Please use the IIS
Administration Tool to reconfigure
your server to run the application in
a separate process.

Is it possible to do this under IIS6 and Windows Server 2003?

Best Answer

To clarify: Each app pool binds to the .NET framework of the first web site that uses it, in order of application startup. That first site will run fine, but all other sites will be restricted to the same app pool. You need at least one app pool per framework version; and in my experience, the most robust setup is one app pool per application - this way, you can switch framework versions without worrying about other applications, and you can kill individual applications through task manager when the need arises.

Related Solutions

How to tell IIS 6 to set the .NET version to 2.0 (not 1.1) When New sites are created

As already mentioned by another, I reference this post whenever I need to change the .NET settings for a site.

As for your question, the following steps (summarized from the linked post) should achieve what you need:

Run aspnet_regiis -lk from any .NET framework folder to list your current settings to help you determine which sites should remain using .NET 1.1. If you know there is a .NET 1.1 site, but it is not explicitly listed by this command, then it is inheriting from the root W3SVC/.
For all .NET 1.1 sites not explicitly listed by the previous command, you will need to force them to use .NET 1.1:
1. Determine the Identifier ID of the site(s) which you want to force to use .NET 1.1. (Through the IIS 6 Manager, you can determine the Identifier of a site by clicking the "Web Sites" folder on the left side of the tool. On the right side, all your sites will be listed, and the Identifier column shows the ID.)
2. From the .NET 1.1 framework folder, run aspnet_regiis -sn W3SVC/<Identifier ID>/ROOT/ where <Identifier ID> is the ID of the site which you want to force to use .NET 1.1.
Finally, change the root W3SVC/ to use .NET 2.0 so that all newly created sites will inherit from the root and default to use .NET 2.0. To change the root, from the .NET 2.0 framework folder, run aspnet_regiis -sn W3SVC/.

You can run aspnet_regiis -lk again to verify your settings.

Session timeout in ASP.NET

Are you using Forms authentication?

Forms authentication uses it own value for timeout (30 min. by default). A forms authentication timeout will send the user to the login page with the session still active. This may look like the behavior your app gives when session times out making it easy to confuse one with the other.

<system.web>
    <authentication mode="Forms">
          <forms timeout="50"/>
    </authentication>

    <sessionState timeout="60"  />
</system.web>

Setting the forms timeout to something less than the session timeout can give the user a window in which to log back in without losing any session data.

Best Answer

Related Solutions

How to tell IIS 6 to set the .NET version to 2.0 (not 1.1) When New sites are created

Session timeout in ASP.NET

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