I was asked to install a proxy on one of our Linux server. Since we used hardware solutions until now, I am quite new in that. I tried to read several documentations but I am still lost.

Here is what I need to do :

We have server 192.168.100.1 which has squid installed. I need to configure the proxy so that

192.168.100.100 can only be accessed throught that proxy. An authentication is necessary. Port of proxy needs to be changed to 7779

So that people have to put in their browser the proxy address 192.168.100.1 including user / password

to access .100

COuld someone PLLEEEEASE give me a hint here ?

i'd suggest you did some background reading on squid, as this is really basic stuff, and the squid.conf file details any step you need. essentially you would define an ip acl in the config file which references the destination server, then use the http_access directive to permit access to it, and presumably nothign else (via an http_access deny all at the end of the list). you may just want to look at using webmin to configure this kind of thing for you, as it does simplify it further still. the config file can look a little daunting, but really it's fairly simple when you reliase you don't care about 95% of it. bear in mind also what you have described can be interpreted quite a few ways. all you've told us about your architecture is that it contains two machines in it somewhere. where is your userbase relativee to the proxy and the server etc... also what kind of authentcation do you want? ntlm authentication into AD (for example) is possible, but my knowledge of it is that it's pretty horribly and invloves a lot of samba. a local passwd lookup is a doodle though. id' really recommend you ask for specific answers to specific questions where possible. but yeah... webmin.