Hi all:

I met a stranger problem. a field of "x-ws.ajax: delta=true" is added after NGINX.

1) Topology client ---------[NGINX] -----------------------[IIS 6.0] server ^___Act as reverse proxy

NGINX( 1.0.5 and keep-alive enabled)

-------------------------------------------------------------------------------------------------- 2) Issue (1) We can not list a directory from IIS server. (2) If we bypass NGINX, everything is good well.

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3) we sniff on both sides of NGINX and compare the pcap file, we found an extra-field is added after NGIX.

---------------------------------------------------------------Before NGINX------------------------------------------------------------- POST /server/WorkFlowProcess/WaittingProcessWorkFlow.aspx?_dc=1313745754796 HTTP/1.1 Connection: keep-alive Host: www.abc.com Accept: */* Accept-Language: en x-requested-with: XMLHttpRequest Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Referer: http://www.abc.com/server/WorkFlowProcess/WaittingProcessWorkFlow.aspx Accept-Encoding: gzip, deflate User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) Content-Length: 1172 Cache-Control: no-cache Cookie: ASP.NET_SessionId=2lscnq45aaihogaw0igsoi45

----------------------------------------------After NGINX--------------------------------------------------------------------------------- POST /server/WorkFlowProcess/WaittingProcessWorkFlow.aspx?_dc=1313745754796 HTTP/1.1 Accept: */* Accept-Language: en x-ws.ajax: delta=true * <============Here, the filed is added* x-requested-with: XMLHttpRequest Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Referer: http://www.abc.com/server/WorkFlowProcess/WaittingProcessWorkFlow.aspx Accept-Encoding: gzip, deflate User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) Host: www.abc.com Content-Length: 1172 Connection: Keep-Alive Cache-Control: no-cache Cookie: ASP.NET_SessionId=2lscnq45aaihogaw0igsoi45 ============================================================================

We suspect that the extra field is not recongized by server.

My question is : 1) what does it means? I can not find any usful information from google, there is no such source code in nginx code tree. 2) what does it impact on?

Appreciate your help at advice.

thanks George