NT 4.0 Workstation, Windows 2000 Professional and XP Professional all come with a limit of ten simultaneous connections. When there are more than ten active connections, you might see one of the following:
The page cannot be displayed There are too many people accessing the Web site at this time. |
or
| HTTP 403.9 - Access Forbidden: Too many users are connected |
These operating systems should be used for testing your ASP applications, not deploying them or hosting them in the real world. You will need to get a flavor of Server to do this. If you are developing locally and find that you are triggering this error even from the traffic of one or two users, disable HTTP Keep-alives for the site. These can maintain connection counts even for inactive users, but if you disable them, you will be much less likely to see adverse affects from local development. RIght-click the web site in Internet Services Manager, hit Properties, and on the Web Site tab, there is a checkbox labeled "HTTP Keep-Alives Enabled." Uncheck this box, hit Apply, OK, and exit Internet Services Manager. You may need to restart the IIS service for the change to be applied. See
KB #262635 for more information.
You can also see
KB #122920 for information about inbound connection limitations in NT 4.0 Workstation or Windows 2000 Professional, or
KB #314882 for a Windows XP version.
But come on, is there a workaround? Well, yes, there is, though I don't recommend it.
It's been suggested to use Apache or another web server that runs in Windows (though you won't be able to use ASP without a third party product, obviously; see
Article #2181). The limitation in Workstation / Professional is enforced at the IIS level, not the TCP level, so it is possible to use a different web server to bypass the limitation — but you will still be violating your license agreement.
Given that you are already using a lower-powered operating system by nature, you might think hard before allowing everyone in your office (or worse) free reign over your machine by utilizing this workaround. In other words, it might be time to move your application to the Intranet server, your data center, or to a real live hosted solution, rather than continue trying to "get by" with using your desktop to serve content to more than a handful of people.