Enter X-Forwarded-For (XFF). This article explores how A10 handles this critical header, how to configure it, and the security pitfalls that come with it. The X-Forwarded-For header is a de facto standard (defined in RFC 7239, though superseded by Forwarded ). Its syntax is a simple comma-separated list:
If your backend server reads only the first IP (leftmost) as the client, it will believe the request is coming from 127.0.0.1 (localhost)—bypassing all ACLs. a10 x-forwarded-for
In the CLI: