Removing Etag and Last-Modified Headers from IIS

Question

Do you know what to prevent re-checking files in the browser cache and subsequent 304 responses by completely removing the ETag response and Last-Modifed headers?

Of course, this is easy in Apache, but as clear as dirt in IIS 6. Does anyone know how to remove both of these headers in IIS?

Answer 1

Programmatically, using an HTTP module, something like this (based on Luke's SO response ):

namespace HttpModules { using System; using System.Web; public class RemoveExtraneousHeaderModule : IHttpModule { /// <summary> /// Initializes a module and prepares it to handle requests. /// </summary> /// <param name="context">Provides access to the request context.</param> public void Init(HttpApplication context) { context.PreSendRequestHeaders += this.OnPreSendRequestHeaders; } /// <summary> /// Disposes of the resources (other than memory) used by this module. /// </summary> public void Dispose() { } /// <summary> /// Event raised just before ASP.NET sends HTTP headers to the client. /// </summary> /// <param name="sender">Event source.</param> /// <param name="e">Event arguments.</param> protected void OnPreSendRequestHeaders(object sender, EventArgs e) { NameValueCollection headers = HttpContext.Current.Response.Headers; headers.Remove("Server"); headers.Remove("ETag"); headers.Remove("X-Powered-By"); headers.Remove("X-AspNet-Version"); headers.Remove("X-AspNetMvc-Version"); } } } 

The module is installed via web.config under <system.web> for IIS 6 and under <system.webServer> for IIS 7.