server with 400 sites, all visitor have same IP (my server IP)

[ezak]

hi support,

I have pig problem here
I tried to install nginx admin manytimes
but NO Luck

all my websites (400 website), all visitors in that websites have my
dedicated IP address 

that make all members have login problem in there forum coz the same IP
dedection

some information for that same IP
when run

# netstat -plan|grep :80|awk {'print $5'}|cut -d: -f 1|sort|uniq -c|sort
-nk 1

     15 41.238.235.138
     16 41.254.2.253
     18 197.122.191.18
     18 41.191.61.76
     20 41.35.96.40
     21 41.237.206.115
     34 217.55.196.72
     40 188.48.101.225
    140 188.48.49.204
   1556 xx.xx.xx.xx (my main server dedicated ip address)



nginx.conf

user  nobody;
# no need for more workers in the proxy mode
worker_processes  2;
error_log  /var/log/nginx/error.log info;
worker_rlimit_nofile 20480;
events {
 worker_connections 5120; # increase for busier servers
 use epoll; # you should use epoll here for Linux kernels 2.6.x
}
http {
 server_name_in_redirect off;
 server_names_hash_max_size 10240;
 server_names_hash_bucket_size 1024;
 include    mime.types;
 default_type  application/octet-stream;
 server_tokens off;
 sendfile on;
 tcp_nopush on;
 tcp_nodelay on;
 keepalive_timeout  5;
 gzip on;
 gzip_vary on;
 gzip_disable "MSIE [1-6]\.";
 gzip_proxied any;
 gzip_http_version 1.1;
 gzip_min_length  1000;
 gzip_comp_level  6;
 gzip_buffers  16 8k;
# You can remove image/png image/x-icon image/gif image/jpeg if you have
slow CPU
 gzip_types    text/plain text/xml text/css application/x-javascript
application/xml image/png image/x-icon image/gif image/jpeg
application/xml+rss text/javascript application/atom+xml;
 ignore_invalid_headers on;
 client_header_timeout  3m;
 client_body_timeout 3m;
 send_timeout     3m;
 reset_timedout_connection on;
 connection_pool_size  256;
 client_header_buffer_size 256k;
 large_client_header_buffers 4 256k;
 client_max_body_size 200M; 
 client_body_buffer_size 128k;
 request_pool_size  32k;
 output_buffers   4 32k;
 postpone_output  1460;
 proxy_temp_path  /tmp/nginx_proxy/;
 client_body_in_file_only on;
 log_format bytes_log "$msec $bytes_sent .";
 include "/etc/nginx/vhosts/*";
}

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,223649,223649#msg-223649