Http header 304 and caching?

Royi Namir asked:

Our company uses these settings( don’t ask me why) – for every request they want a new request from server. this is an intranet system which uses only IE.

They defined it in :

enter image description here

We also have windows authentication NTLM in the iis7.

I have 2 questions please.

Question #1)

when the browser make a request ( css ) :

(leave the 401 response for now – this is how ntlm works)
enter image description here

He is requesting it with if-modified-since header.

why is he adding this header ? How can I configure it ? why doesn’t he use the settings from IE and try to download it each time – as I showed in the first picture ?

Question #2)

The response ( after ntlm negotiation) for that was :

Response with Not-modified which is 304 header. and I assume its because we sent the request with the if-modified-since header.

But there is a problem.

He is actually tells me to download from my cache.

But I told him explicitly in the IE settings – not to load from cache.

Wham am I missing here ?

Thanks a lot.

enter image description here

My answer:


The setup you are asking for is a very bad idea. If you actually roll this out, everything will seem to load slower. Every server you connect to is going to get hammered into smithereens. I don’t know why you’re being asked to do this, but you should find out why, so that you can come up with a reasonable solution to whatever the real problem is.

Plus, you can’t do it with Internet Explorer at all. It has no way to completely disable use of caching (Temporary Internet Files).

One situation you may be running into is with people with roaming profiles having large IE caches that end up getting copied around the network. If this is what the real problem is, then you can tell IE to empty the cache when it exits. There will no longer be any large file copies going on, at least with respect to IE’s cache.


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