How to ignore routes in ASP.NET Core?

If you want to make a static file accessible without the routing condition, simply use the build-in StaticFiles Middleware. Activate it with app.UseStaticFiles(); in Configure Method and put your static files in wwwroot directory. They're availible on HOST/yourStaticFile

For more information, refer here

You could write middleware for this.

public void Configure(IApplciationBuilder app) {
    app.UseDefaultFiles();

    // Make sure your middleware is before whatever handles 
    // the resource currently, be it MVC, static resources, etc.
    app.UseMiddleware<IgnoreRouteMiddleware>();

    app.UseStaticFiles();
    app.UseMvc();
}

public class IgnoreRouteMiddleware {

    private readonly RequestDelegate next;

    // You can inject a dependency here that gives you access
    // to your ignored route configuration.
    public IgnoreRouteMiddleware(RequestDelegate next) {
        this.next = next;
    }

    public async Task Invoke(HttpContext context) {
        if (context.Request.Path.HasValue &&
            context.Request.Path.Value.Contains("favicon.ico")) {

            context.Response.StatusCode = 404;

            Console.WriteLine("Ignored!");

            return;
        }

        await next.Invoke(context);
    }
}