How to configure squid to be a transparent proxy

Hi,

I have been researching this topic for some time and I'm not real sure
if I'm going about this the right way. I have a Fedora 4 box running
squid 2.5 and dansguardian 2.8.0.6. This is a standalone machine on a
private network with only one network card. The gateway is a dsl
modem/router which has DHCP enabled. I would like all http traffic
coming from any machine on this private network to be redirected to
this linux box without having to manually configure each Internet
browser. Can this be done this way or do I need to set this linux box
up as the default gateway?

Dear p33gopher

It depends on capabilities of the dsl modem/router. If it can do
port-redirection(or translation) you just need configure the dsl
modem/router to do it as you want, sould be the simplest way. If it
can't do port-redirection(or translation) you need to have another box
as the default GW of the workstations, that can do it. Your Linux box
is a good choice for this new box.
Then you need to enable routing(if people) and do port-redirection(or
translation), using IPTABLES, in your Linux box to redirect specific
traffic that passing trough to your squid, and also configure squid to
operate in transparent mode.

That's all in brief. But you might need some considerations in
network configuration.

Hope it helps.

Best Regards

The modem/router actually has Port Forwarding and Port Triggering
capabilites. It also allows you to assign an ip as a static NAT. I'm
not sure which one I need.

Could you provide me the brand and model?

I'm at work now. So, I'm not entirely sure if this is the exact model.
Westell w327

This link might help give you some specs.

http://www.westell.com/content/produ.../versalink.pdf

What we are looking for is, Port Nerwork Address Translation(PAT or
PNAT). Westell Versalink w327, does not support what we want. We want
the modem/router translate the destination/port of the HTTP traffic
that passes trough the modem/router to be the IP address of the Linux
Box and Port No. which Squid is listening on. What is called "Port
Forwarding" in the manual, I think, is for Forwarding a range of WAN
ports to an IP Address, may be suitable for monitoring.

I brief, According to

http://www.westell.com/content/sales/327W.pdf

I think the modem could not do it

ok, darn. I figured that... :( Ok. So now my question is... what and
how do I configure this linux box to replace the dsl modem/router? II
appologize for my ignorance. I'm fairly new to linux. Here is a
website (one of the many I've found) that outlines how to setup squid
as a transparent proxy.
http://www.linuxsolved.com/forums/ftopic116.html

Here's another for setting up a gateway/firewall
http://yolinux.com/TUTORIALS/LinuxTu...rkGateway.html

I've looked these over at a glace. Do they look correct to you?

It seems they are OK. But in my oppinion the most reliable things
could be found on tldp.org( HOWTOs, Guides - specially Securing and
Optimizing Guide) coz they are official and mainained regularly.

Anyway I guess there would be no problem to use those guides, and If
you would let me review what configuration you will do using those
guides.

Best Regards
--
Mehdi Sarmadi

It seems they are OK. But in my oppinion the most reliable things
could be found on tldp.org( HOWTOs, Guides - specially Securing and
Optimizing Guide) coz they are official and maintained regularly.

Anyway I guess there would be no problem to use those guides, and If
you would let me review what configuration you will do using those
guides.

Best Regards
--
Mehdi Sarmadi

Great, thank you very much for your help. I will look over these and
let you know. I will probably need more assitance.... Do you mind if
I contact you via your e-mail address or continue with my questions on
the forum? :)