Re: ISA 2004: Web Publishing disabling HTTP Compression

From: Michael J. Carter (michael_at_volcanictech.com)
Date: 09/21/04 

Date: Tue, 21 Sep 2004 17:27:55 -0400

Wayne, thanks for the confirmation. I had a feeling that was the case.

Unfortunately, I can't use Server Publishing because I need to publish
multiple web servers on a single IP.

I just seems kind of dumb to disable this. It would have been nice if they
mentioned this anywhere in their documentation.

Thanks again.

"Wayne Berry" <wayne@berryintl.com> wrote in message
news:ODekNvBoEHA.3900@TK2MSFTNGP10.phx.gbl...
> Michael,
>
> Basically compression doesn't work with ISA 2004. ISA 2004
>
> - Strips the compression header when the browser sends it, preventing the
> web server from "knowing" that the client supports compression
> - Doesn't Cache Compressed Responses
> - Doesn't Send Compressed Responses
>
> We (XCache Technologies http://www.xcache.com) write a compression filter
> for ISA 2000 and are working on a Compression filter for ISA 2004. It
> will:
>
> - Ask the web server for a compressed response.
> - Enable ISA 2004 to cache that response
> - Send a compressed response to the browser when the browser asks for it.
>
> -Wayne
>
>
> "Michael J. Carter" <michael@volcanictech.com> wrote in message
> news:uRmeKfBoEHA.3876@TK2MSFTNGP15.phx.gbl...
>> I'm using ISA 2004 and publishing internal web servers using Web
> Publishing.
>> I have enabled HTTP Compression (IIS6) on these sites, and everything
> works
>> if I access the server internally (directly).
>>
>> However, external clients that go through ISA are not getting HTTP
>> Compression.
>>
>> I did some experiments and this is what I found out:
>>
>> I created a test page on my internal server that dumps the headers. If I
>> access the site internally, I see this header:
>>
>> Accept-Encoding: gzip, deflate
>>
>> And all is well.
>>
>> However, if I access it from an external site, the header is no longer
>> there.
>>
>> I then created a simple Web Filter and installed it on the ISA Server.
> This
>> filter simply logs the Accept-Encoding header during the PREPROC_HEADERS
>> notification. The logs show that the Accept-Encoding header is present.
>>
>> Therefore, somewhere between the time my filter executes and ISA
> dispactches
>> the request to my web server, the Accept-Encoding header is stripped. I
>> understand that HTTP Filtering of the response body and HTTP compression
>> don't mix. However, I have disabled every Web Filter (except the one I
>> added) and I'm still seeing this problem.
>>
>> Is this normal behavior?
>>
>> Am I going to have to implement HTTP Compression in my filter and not use
>> the one built in to IIS 6?
>>
>> Oddly, I found this quote on Microsoft site:
>>
> http://www.microsoft.com/technet/prodtechnol/isa/2004/plan/httpfiltering.mspx
>>
>> Q. Can I cache compressed content?
>> A. In a Web publishing scenario, ISA Server allows the traversal of
>> compressed responses from the Web server to the client, if the client
> sends
>> an Accept-Encoding header indicating that it will accept compressed
> content.
>> However, compressed content will not be cached. Note that ISA Server does
>> not support traversal of compression responses in a forward proxy
> scenario,
>> and does not support inspection of compressed response bodies in any
>> direction.
>>
>>
>>
>>
>> So it appears that this is supposed to work. What am I missing here?
>>
>> BTW: I disabled HTTP Caching, and it is still not working.
>>
>> Michael
>>
>>
>
>

Relevant Pages

  • SSL Publishing issue (error 500 Target principal name is incorrect - 2146893022)
    ... I am having some issues publishing my SSL sites via ISA 2004. ... The ISA server uses internal DNS servers to name resolution. ... exported as PFX and imported onto both web servers and the ISA server. ...
    (microsoft.public.isa.publishing)
  • RE: ISA 2004 Connectivity to Internal Web Servers
    ... Open ISA Server 2004 Admin Console ... Bypass proxy for Web servers in this network ... Sill in Web Browser tab, click Add button to open Add Server window. ... when all internal clients attempt to ...
    (microsoft.public.isa)
  • Re: SSL Publishing issue (error 500 Target principal name is incorrect - 2146893022)
    ... servers I have assigned a cert with their internal FQDN and changed the ISA ... > The ISA server uses internal DNS servers to name resolution. ... > exported as PFX and imported onto both web servers and the ISA server. ...
    (microsoft.public.isa.publishing)
  • Re: Securing web site with redundancy ?
    ... Load balancing inserts complexity though. ... Securing web site with redundancy? ... If one server goes down the DNS ... My web servers are web servers only, not at all DNS servers ... ...
    (Security-Basics)
  • Free SSL Buddy for Indy/IntraWeb
    ... SSLBuddy will help you... ... Generate Certificate Requests - SSLBuddy asks you simple, ... certificates suitable for testing secure web servers. ... and key.pem files in the format understood by the server. ...
    (borland.public.delphi.thirdpartytools.general)