actual IP not logged when requests come forwarded by a reverse proxy

[Tapas Mishra]

My apache2.conf
http://pastebin.com/uTVKt1wD
and apacche vhost file
http://pastebin.com/QDd3LDZ4
the apche2.conf and vhost file I gave the link are the machine on LAN
where site is actually hosted.
When some one from internet access the site then I expect a log of IP in
access.log
instead of which I see the IP of machine which is working as Reverse
Proxy server for all such requests.
What mistake did I do above.

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