What is HTTP forwarder?
The X-Forwarded-For (XFF) HTTP header field is a common method for identifying the originating IP address of a client connecting to a web server through an HTTP proxy or load balancer. The X-Forwarded-For HTTP request header was introduced by the Squid caching proxy server’s developers.
What is X powered by?
X-Powered-By is set by various servers to say what kind of server it is. Software installed on that server might override the server’s default. There is an argument that giving this information to clients gives information that can only serve to help attackers (just a little bit: saves working out what kind of server).
Should custom headers start with X?
RFC6648 recommends that you assume that your custom header “might become standardized, public, commonly deployed, or usable across multiple implementations.” Therefore, it recommends not to prefix it with “X-” or similar constructs.
Can headers have Underscores?
Please note that using underscores in headers is perfectly valid per the HTTP spec, but Nginx, by default, will ignore them.
What is the difference between X-Forwarded-Proto and X-Forwarded-For?
X-Forwarded-For: the originating IP address of the client connecting to the Heroku router X-Forwarded-Proto: the originating protocol of the HTTP request (example: https) X-Forwarded-Port: the originating port of the HTTP request (example: 443)
Why does the Heroku router have to make a decision?
These behaviors are undefined by the original specifications, and the Heroku router has to make a decision regarding them in order to provide consistent behavior.
What is the difference between X-Forwarded-For and forwarded HTTP header?
RFC 7239 standardized a Forwarded HTTP header with similar purpose but more features compared to the X-Forwarded-For HTTP header. An example of a Forwarded header’s syntax: HAProxy defines the PROXY protocol which can communicate the originating client’s IP address without using the X-Forwarded-For or Forwarded header.
What HTTP methods are supported by Heroku?
The Heroku HTTP stack supports any HTTP method (sometimes called a “verb”), even those not defined in an RFC, except the following: CONNECT. Commonly used methods include GET, POST, PUT, DELETE, HEAD, OPTIONS, and PATCH.