Hi, Just want to ask anyone that know how Apache reverse proxy work. I am trying to understand a setup for a friend. web server running on windows server with internal ip 192.168.1.20. DNS record for www.abcd.com.au with 203.x.x.10. Linux box (Ubuntu) is setup as reverse proxy server with external eth0 with ip 203.x.x.10 and internal eth1 ip 192.168.1.10. Below is the config from /etc/apache2/site-enable <VirtualHost *> ServerName mail.abcd.com.au ServerAlias *.abcd.com.au RewriteEngine on RewriteRule /.* http://www.abcd.com.au/ [R] </VirtualHost> Base on the above config, I unable to understand how Linux able to redirect web client to the internal web server or from webserver back to client browser. /etc/hosts have www.abcd.com.au point to 192.168.1.20. Regards, Theng