Of cource Eliezer, thanks a lot! Yes, of course, I mean dns lookup by resolve. (It has been set up by an external company) The chain is very simple, just one after the other: clients (FF) ---> Squid1 (LAN) ----> Squid2 (somewhere in between) ---> Squid3 (at the Internet) This chain is being used by the users when accessing the Internet. It's the same behaviour for any possible URL. I took just a rare one so I could find it easily in the tcpdump output. I just checked the squid1 and squid 3 (squid 2 same as squid1). Squid one contacts the internal dns server which forwards to the root servers. But the dns answer to the query is not given to the next proxy in the chain, so it's then useless. The squid 3 accesses the dns root servers directly and then it forwards the http request to the final server. The problem might be that the squid 1 also is being used for internal "direct access", i.e without a parent. My question is now, is it possible for the squid to decide when to use a dns lookup? For example just in the case when the access to a specific URL goes directly to the web server but not if forwarded to the next cache parent? Jannis ----- Ursprüngliche Mail ---- Von: Eliezer Croitoru <eliezer@xxxxxxxxxxxxxxxxxx> An: squid-users@xxxxxxxxxxxxxxx Gesendet: Donnerstag, den 28. April 2011, 13:51:17 Uhr Betreff: Re: Does any cache in a proxy chain but the last one need to resolve URLs? On 28/04/2011 12:25, Jannis Kafkoulas wrote: > Hi, > > We have a proxy chain of 3 squids (v2.7, RHEL5). > In my opinion only the last one needs really to resolve the URLs name in order > to > > send the request directly to the web servers ip address in the Internet. > > Would it also work if the first two proxies wouldn't resolve? by resolve you mean dns lookup? > And how can that be prevented? it depends on how the chain is built. if you can picture for me the infrastructure and some url examples i can try to help you with it. Eliezer > Thanks >
