Redirect http traffic with DNS server?

[netadmin]

On my network, the modem is plugged into a Linksys router. The router is not used for DHCP. On the Windows 2003 domain controller, DHCP and DNS servers are setup and operational.

 

I have now setup Dansguardian and Squid. Is there any way I can change something on the DHCP or DNS server to automatically redirect all HTTP traffic to the Dansguardian server?

 

I would just configure the proxy server option in IE, but we have lots of students who bring their laptops and having them all have to change the proxy setting would cause too many problems.

 

Any ideas? :?:

[Ric_]

You need to set up Squid as a transparent proxy and set the squid box as your gateway.

[Geoff]

set the squid box as your gateway.

 

You can avoid this by having the box inline as a layer 2 bridge. That way it's transparent to the client/server but still able to intercept traffic.

[tom_newton]

Or, you can set DHCP option 252. This can be done in w2k, but don't ask me how.

the DHCP server must be authoritative (probably already is)

 

You then need a web server (squid box? - our customers use the built in server on Guardian) to serve a proxy.pac file, which is renamed wpad.dat (again, our s/w serves the same file under either name). The option 252 text should point to this file.

 

Clients then need to be set to "automatically detect proxy settings", which is the default in IE (iirc).

 

Caveats:

Won't work in firefox, at all.

Does not force the issue - block port 80 on your firewall

 

there was going to be another caveat, but someone phoned and made me forget it. Sorry....