HttpContext extension method to set sub domain safe cookie

HttpContextBaseExtenstions.cs

public static class HttpContextBaseExtenstions
{
    public static void SetSubdomainSafeCookie(this HttpContextBase context, string name, string value)
    {
        var domain = String.Empty;
    
        if (!context.Request.IsLocal)
        {
            var domainSegments = context.Request.Url.Host.Split('.');
            domain = "." + String.Join(".", domainSegments.Skip(1));
        }
        else
        {
            domain = context.Request.Url.Host;
        }
    
        var cookie = new HttpCookie(name, value);
        
        if(!String.IsNullOrEmpty(domain)
        {
            cookie.Domain = domain
        }
            
        context.Response.SetCookie(cookie);
    }
}

// usage
public class MyController : Controller
{
    public ActionResult Index()
    {
        Context.SetSubdomainSafeCookie("id", Guid.NewGuid().ToString());
        return View();
    }
}