Reverse Mappings on a Proxy Server

Hi,

Reverse mappings don't work excatly in a proxy-server. Reverse mappings are configured at the unix server, they build the way back of the request the user or application. When you start a transaction on a server, your client machine connects to the server "via" network with an IP address, the application request travels through the net (routers, bridges, firewalls, or what ever), the server answers the request to a map of ip addresses that route the answer back to the client machine. Of course this is a very simple and two line description. The proxy server is a cache that allows multiple users to access resorces at the internet (intranet or extranet) these resources can be, http, pop3, smtp, ftp, tftp, what ever. You may find more info about proxy servers at www.squid-cache.org, and for the reverse mappings at :

www.bsd.org
www.geek-girl.com/unix.html

Hope it helps

First let us understand how proxy works.
It's principle is based on many to one connection.
You connect proxy to internet (one connection) and allow all users (many connections) to go to proxy to connect to internet.
In case of rev-proxy role is reversed. Many Users will be comming from internet sites to access
application servers hosted inside i.e.on intranet.
one can create mappings on single proxy servers to access number of application servers.
For example...
forward mapping..
http://proxy.domain/s1 http://applserver1.domain
reverse mapping..
http://applserver1.domain http://proxy.domain/s1
Similarly for second application server...
Forward mapping..
http://proxy.domain/s2 http://applserver2.domain
reverse mapping..
http://applserver2.domain http://proxy.domain/s2
and so on..
This way one can define number of mapping.
Make sure that proxy server is able to talk to application servers on application port, in above example port 80.Also proxy is available on port 80 from outside (internet).One can also configure proxy to work as reverse proxy on others ports.One has to ensure all these ports are open on firewall and border routers.
These feature allows more security to application servers as they can be configured and connected in intranet. Only proxy needs to be in DMZ.