Asp.net Sharepoint Authentication

How to Retrieve the PC Name of a Client in ASP.NET Applications

In today’s interconnected world, understanding the machines your users are operating from can be quite beneficial, especially in internal networks. If you’re working with an ASP.NET application on SharePoint and are looking to retrieve the PC Name of a client using Windows Authentication, you might have encountered some challenges. In this blog post, we’ll dive into a solution that allows you to effectively obtain this information while adhering to your constraints, which avoids client-side scripting when possible.

The Problem: What You Need to Know

When you’re developing in an internal environment, such as with SharePoint 2007 on ASP.NET, you might wonder if there is a way to discover the name of the client’s machine. The usual methods to achieve this could involve the use of JavaScript or other client-side approaches, but in some cases, such as with certain security policies, these may not be acceptable. Instead, you may want a straightforward server-side solution.

Key Considerations:

  • Internal Network: Your application runs on an internal network where users frequently switch PCs.
  • No Client-Side Scripting: You prefer to avoid any JavaScript or ActiveX technologies.
  • Active Directory Access: You have access to Active Directory, which could be useful for resolution.

The Solution: Using DNS Resolution

While you might initially think to use System.Web.HttpRequest.UserHostName, it only gives you the IP address. Instead, there’s a more effective method using the System.Net namespace to access DNS information. Here’s how you can retrieve the PC Name:

Step-by-Step Implementation

  1. Use the User’s IP Address: First, access the user’s connected IP address from the HTTP request.
  2. DNS Lookup: Utilize the DNS capabilities provided in .NET to resolve that IP address to a hostname. This is possible if there is a DNS server configured in your network.

Here’s a snippet of code to achieve this:

string userHostAddress = Page.Request.UserHostAddress; // Get the user's IP address
string pcName = System.Net.Dns.GetHostEntry(userHostAddress).HostName; // Resolve to hostname

Important Notes:

  • DNS Server Requirements: Ensure that there is a working DNS server on your network—this is crucial for the resolution to work.
  • IP to Hostname Resolution: Keep in mind that this approach relies on the active registration of hostnames in the DNS for successful lookups.

Conclusion: Simplifying Client Identification

By employing the DNS resolution approach we discussed, you can efficiently retrieve the PC Name of a client in an ASP.NET application within a controlled environment like SharePoint. This method avoids the complications often associated with client-side scripting and remains user-friendly. Remember to ensure that your network’s DNS setup is correctly configured to facilitate hostname resolution.

With these principles and methods in mind, you can enhance your application’s functionality and cater to the needs of your users more effectively. Happy coding!