Might be missing this, from an old Apache config: # Configuration for mod_rpaf <IfModule mod_rpaf.c> RPAFenable On RPAFproxy_ips 192.168.2.123 # RPAFsethostname host.your.domain </IfModule> # End of mod_rpaf. Posted at Nginx Forum: http://forum.nginx.org/read.php?2,249698,249710#msg-249710