Use of HTTP.sys Server
💡 Concept Name
HTTP.sys Server
📘 Quick Intro
HTTP.sys is a Windows-only web server for ASP.NET Core applications. It offers features like Windows authentication, response caching, and direct kernel-mode networking support—making it ideal for high-performance or intranet applications.
🧠 Analogy / Short Story
Think of HTTP.sys like a private lane on a highway, reserved for VIPs. While Kestrel is the public highway that's flexible and open to all platforms, HTTP.sys is optimized for Windows—offering tighter security and priority speed for internal traffic.
🔧 Technical Explanation
HTTP.sys is built on top of the Windows HTTP Server API and allows ASP.NET Core apps to be hosted without using IIS or Kestrel. It's a self-hosting option that supports:
- 🔒 Windows authentication
- 📶 Port sharing
- 🚀 Response caching
- 🛡 SSL directly at kernel level
Because it runs in kernel mode, it offers performance benefits for high-throughput, low-latency scenarios.
🎯 Purpose & Use Case
- ✅ Enterprise intranet applications
- ✅ Apps requiring Windows authentication
- ✅ Hosting without IIS or reverse proxies
- ✅ APIs serving LAN clients with low latency
- ✅ High-performance, secure Windows-only hosting
💻 Real Code Example
// Program.cs
var builder = WebApplication.CreateBuilder(args);
builder.WebHost.UseHttpSys(options =>
{
options.Authentication.Schemes =
Microsoft.AspNetCore.Server.HttpSys.AuthenticationSchemes.NTLM;
options.Authentication.AllowAnonymous = false;
});
var app = builder.Build();
app.MapGet("/secure", () => "Secure endpoint under HTTP.sys");
app.Run();
Key Highlight: This setup uses HTTP.sys for Windows-authenticated endpoints with no reverse proxy.
❓ Interview Q&A
Q1: What is HTTP.sys?
A: A Windows-only web server used to host ASP.NET Core applications without IIS or Kestrel.
Q2: Key benefit of HTTP.sys over Kestrel?
A: Kernel-mode performance and direct Windows integration like authentication and port sharing.
Q3: Is HTTP.sys cross-platform?
A: No, it runs only on Windows OS.
Q4: Can HTTP.sys serve public web traffic directly?
A: Yes, unlike Kestrel, HTTP.sys is designed to handle direct internet traffic.
Q5: Does HTTP.sys require IIS?
A: No, it can work as a standalone server without IIS.Q6: When should I choose HTTP.sys over Kestrel?
A: When Windows-specific features or high internal security is needed.
Q7: Can HTTP.sys support HTTPS?
A: Yes, and it handles SSL at kernel level for efficiency.
Q8: How to enable HTTP.sys in ASP.NET Core?
A: Use `UseHttpSys()` method in `Program.cs` or `CreateHostBuilder` setup.
Q9: Does it support WebSockets?
A: No, Kestrel is preferred for scenarios needing WebSockets.
Q10: Can HTTP.sys be used with Docker?
A: Only if the container is based on Windows, not Linux.
📝 MCQs
What is the primary OS supported by HTTP.sys?
Answer: Windows
Which server works in kernel-mode in ASP.NET Core?
Answer: HTTP.sys
Can HTTP.sys handle HTTPS?
Answer: Yes
Does HTTP.sys require IIS?
Answer: No
Which is better for WebSocket support?
Answer: Kestrel
Is HTTP.sys cross-platform?
Answer: No
Which method enables HTTP.sys in code?
Answer: UseHttpSys()
Is HTTP.sys ideal for Linux hosting?
Answer: No
What is a benefit of kernel-mode performance?
Answer: Low latency and high throughput
Does HTTP.sys support port sharing?
Answer: Yes
💡 Bonus Insight
HTTP.sys is an advanced option for specialized scenarios, such as enterprise intranets or high-security environments. It may not be as flexible as Kestrel, but it's perfect where Windows integration is a must.
📄 PDF Download
Need a handy summary for your notes? Download this topic as a PDF!