Re: [squid-users] transparent proxy over transparent proxy

On 13/07/11 16:53, WiNET . wrote:
> On Wed, Jul 13, 2011 at 11:45 AM, Amos Jeffries wrote:
>>
>> Please explain...
>>
>> What type of "transparent"? and how is the network "set"?
>>
>> What type of "transparent"?
>> And how exactly do you configure "over" transparency from the client end?
>>
> i only know how set the usual one, i don't know if there are other
> type of transparent.
>
> http_port 3128 transparent
>
> and here is my simple configuration:
> http://imageshack.us/photo/my-images/195/unled1fi.jpg/
>

Thank you.

>>
>> which?
>>
>> which other one? does it even store the objects wanted?
>>
>
> proxy1 requests from proxy2 doesn't get HIT, which means, proxy1
> downloading the files directly from internet without getting HIT from
> proxy2. but if i put a client, between the proxy1 and proxy2, the
> client will get HIT for cached objects from proxy2.
>
> http://imageshack.us/photo/my-images/807/unled2gj.jpg/
>

Because the way chained proxies work proxy1 is just another client to
proxy2.

  Are they both caching? that would make proxy1 only pass requests
through proxy2 when the object is expired/stale. In that case both
proxies will detect it as a MISS at once, but HIT only get as far as the
first proxy.
  proxy2 can only be a HIT if some source other than proxy1 caused that
object to be cached or updated before proxy1 had a MISS/REFRESH on it.

So...
  Two proxies chained like this only really make sense if one is not
caching (proxy2 usually for efficiency), or if there are multiple
proxies/clients plugged into router2, or if the cache space available to
proxy1 is smaller than the one able to be stored in proxy2.

Also, proxy1 can use cache_peer directive to pass requests through
proxy2. There is no need for it to be transparent/intercepting at any
level other than the one directly next to the client.

Amos

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