The wikipedia description of the HTTP header X-Forwarded-For is: X-Forwarded-For: client1, proxy1, proxy2, ... The nginx documentation for the directive real_ip_header reads, in part: This directive sets the name of the header used for transferring the replacement IP address. In case of X-Forwarded-For, this module uses the last ip in the X-Forwarded-For header for replacement. [Emphasis mine] The
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