Hi Maxim/Valentin, Thanks for your response. Both port_start and port_end are being used by the mod_security nginx module. Failure to set port_start is causing a Segmentation Violation when mod_security is enabled and a request with absolute URI is sent. Thanks, -anirudh Posted at Nginx Forum: http://forum.nginx.org/read.php?2,255493,255516#msg-255516