How To Stop Caching By ISP Proxy Servers

[Meron Lavie]

We have written an asp.net app, which is apparently being cached by various
British ISP's, and this is recking havoc with our app, as the proxy servers
apparently are disregarding the session id within the URL (we work
cookieless), such as www.widgets.com/(asdiufya09r8)/mypage.aspx, and thus
can not identify to which user/session each page belongs.

We have tried all the textbook solutions, such as:

<%@ outputcache duration="1" varybyparam="none" Location="None" %>

<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="Cache-Control" content="no-cache">
<meta http-equiv="Expires" content="0">

Response.Cache.SetExpires(DateTime.Now.AddMonths(-1));

<META HTTP-EQUIV="Cache-Control" CONTENT="Public">
<meta http-equiv="Cache-Control" content="no-store">

<meta http-equiv="Cache-Control" content="must-revalidate">

We'd be grateful for any suggestions how to absolutely block caching.



TIA,

Meron Lavie

 

[bruce barker]

this is no way to force a proxy to honor your caching request, they are only
hints. if the proxyserver is ignoring the no-cache, url decoration is a
common way to invaldate the cache.

myurl.aspx?r=<random number>

just tack a new randowm number on every page request. (you will need to use
client code to rewrite the postback url if you are using asp.net's postback
model). a filter could also do the work.




-- bruce (sqlwork.com)

 

[Mark Kreimerman]

Bruce,



We have also tried passing the random number to the URL, but it didn't help.

In addition the proxy might consider a Session ID as a part of the link as a
un-cached page and bring it from the server, but unfortunately the old
cached URL(with different Session ID) comes from the proxy.



Best regards,

Mark

 

[Scott M.]

You may want to try:

<% Response.CacheControl = "private" %>