Dear Sir,

I want to deliver internet through proxy server via dhcp service.

My ethernet is configured dhcp and users can get IP address through my DHCP server, and on the same redhat 5 enterprises computer squid has been configured

And I want to deliver internet without change any configuration in the properties of Internet Explorer for proxy server config.

It has to search proxy server automatically.

So please help me where and how i should i configure in dhcpd.conf or, where or, how to configure in squid.conf, so that user can access Internet from squid service via dhcp service with out any changes in their internet explorer properties.

Please help me, to get success in my project.

check out wpad, which seems to be what you're after. Note this is purely a windows issue, nothing to do with Squid.

Is there no scope for modifying DHCP to redirect their default gateways to be the proxy server? Look at smoothwall maybe?

well if it's just a local subnet, you possibly don't *want* a default gateway at all...

How else are they going to get access to the internet without a default gateway?

Refer this urls
http://www.linuxquestions.org/questi...-proxy-701710/
http://wiki.squid-cache.org/SquidFaq/InterceptionProxy
without client side configuration(web browser settings) web access is possible but transparent proxy will not know how to deal with https, gopher, SSL, or FTP, so you will have to handle these protocols using iptables