ISP cache

Hi,


When I type any URL into my browser, I can see that the query is going to
a computer called cache.myisp (say).com . However I don't have a proxy
server set in my browser or anything. How is my ISP pulling this off?

Thanks,

Schewdent.

Schewdent wrote:

> Hi,
>
>
> When I type any URL into my browser, I can see that the query is going to
> a computer called cache.myisp (say).com . However I don't have a proxy
> server set in my browser or anything. How is my ISP pulling this off?
>
Google for "transparent proxy". It's usually done with squid.

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Schewdent wrote:

> Hi,
>
>
> When I type any URL into my browser, I can see that the query is going to
> a computer called cache.myisp (say).com . However I don't have a proxy
> server set in my browser or anything. How is my ISP pulling this off?
>
> Thanks,
>
> Schewdent.

Using a transparent proxy.

iptables -t nat -A PREROUTING -p tcp --dport 80 -i eth0 -j REDIRECT
--to-port 8080

where .. say, port 8080 is the proxy of that isp. That's how an ISP
can regulate the surfing, if they want to. Mostly used in corporate
environment. Easy on sysadmins,cause they don't have to walk up to
every machines for setting up the proxy settings. And it's easy on the
bandwidth usage serving you the frequent used files from their cache.

It has it's downside too. Like you might be served with older
contents, even if the actual site has been updated. But, a well
configured proxy (which checks time-stamping and other stuffs) and
proper tag like <META HTTP-EQUIV="Pragma" CONTENT="no-cache"> on web
page won't let that happen.

--
raqueeb hassan
congo (drc)