config toc

Author: Rick-Anderson

aspnetcore/diagnostics/asp0028.md

@@ -0,0 +1,49 @@
+`IPv6Any` is preferred to `Any` because `Any` is slower than `IPv6Any`. In some cases, `Any` may not work at all. `Any` has performance problems due to the [underlying System types implementation](https://github.com/dotnet/runtime/issues/82404).
+
+`127.0.0.1` is the IPv4 loopback address. `::1` is the IPv6 loopback address. `Any` is the wildcard address for IPv4. `IPv6Any` is the wildcard address for IPv6.
+
+Currently, when using  HTTP/1.x or HTTP/2.0:
+
+* `localhost` resolve to `[::1]`.
+* `[::1]` isn't accepted by the server, which forces a retry using `127.0.0.1`, and the cycle continues.
+
+Using `Any` with the preceding conditions is reported with a diagnostic message:
+
+```csharp
+.UseKestrel().ConfigureKestrel(options =>
+{ 
+    options.Listen(IPAddress.Any, ...);
+})
+```
+
+## Rule description
+
+The recommended way to configure Kestrel to listen for incoming connections on all available `IPv6` network interfaces is with `IPv6Any`.
+
+## How to fix violations
+
+For the problematic code, replace `Any` with `IPv6Any`:
+
+```diff
+.UseKestrel().ConfigureKestrel(options =>
+{ 
+-   options.Listen(IPAddress.Any, ...);
++   options.Listen(IPAddress.IPv6Any, ...);
+})
+```
+
+Alternatively, use the `ListenAnyIP` method without specifying any argument:
+
+```diff
+.UseKestrel().ConfigureKestrel(options =>
+{ 
+-   options.Listen(IPAddress.Any, ...);
++   options.ListenAnyIP(...);
+})
+```
+
+## When to suppress warnings
+
+The `ASP0028` diagnostic has a Information level severity. Suppress warnings if your intention is to disable `IPv6` usage completely on the server, although this comes with the risk of the performance problems mentions in this article
+
+`IPv6` can be disabled either system-wide, or for .NET only via the [AppCtx switch or environment variable](https://devblogs.microsoft.com/dotnet/dotnet-6-networking-improvements/#an-option-to-globally-disable-ipv6)

aspnetcore/toc.yml

@@ -1496,6 +1496,8 @@ items:
             uid: security/authentication/index
           - name: Choose an identity solution
             uid: security/how-to-choose-identity
+          - name: Configure OpenID
+            uid: security/authentication/configure-oidc-web-authentication
           - name: ASP.NET Core Identity
             items:
               - name: Overview