None
FI
What is X-Forwarded-For and when can you trust it?
[]
HTTP Toolkit
Note that the last proxy will not add its own IP address to the list, because that's already available: if the receiver of the request cares about who is calling it directly, they can combine the X-Forwarded-For with the request's source IP address from the incoming connection, e.g: req.connection.remoteAddress in NodeJS.