SURVEY - everyone welcome.

The results of my struggle with mod_deflate

[mipapage]

After strugging thru trying to get mod_deflate working on my server [webmasterworld.com], I managed to track the problem down to my firewall.

The short story is, my firewall was not allowing my browsers to send either HTTP_REFERER or HTTP_ACCEPT_ENCODING data.

---

I was wondering how many people use firewalls that do the same?
If people could check their browsers with one of the two methods below and share their results (browser type, firewall, os), it will be interesting to see how widespread (if at all) this 'problem' is.

The Test
Browsers like IE6, Firebird, Mozilla and Opera (for example) should accept gzip encoding. Two ways that I know of checking if your browser is accepting compressed data are:

1. You can check your browser here: ht*p://www.performancecorps.org/browser_check.php
   
2. Or simply make a php file on your server with the following contents, and view it:
   <?php
   print_r ($_SERVER);
   ?>

With method one, what interests you is the 'ACCEPTED ENCODINGS' value. If 'ACCEPTED ENCODINGS' does not appear in the left hand column, something is up. Try dropping your firewall, refresh, and see if it appears.

With method two, on my machine, the values for the problem HTTP's turn up as

[HTTP________________] => ~~~~~ ~~~~~~~

or not at all when my firewall is on, but appear normally when my firewall is down (i.e.

[HTTP_ACCEPT_ENCODING] => gzip, deflate

and

[HTTP_REFERER] => ht*p://localhost/

NOTE With this test you may have to launch a new browser window to see the changes when turning on or off your firewall.

---

My Results

Norton Internet Security 2003, winXP.
Firewall up, none of Firebird, Mozilla, Opera 7.11, IE5, 5.5, 6 will accept that data.
Firewall down, they all accept the data.

[jdMorgan]

mipapage,

I was hoping you'd get a better response on this, as I have little to offer. I'm stuck behind an HTTP/1.0 proxy on a satellite-based ISP. Despite the fact that my browsers might accept gzip encoding, the proxy does not.

Therefore, I get a big fat zero on your survey. :(

In general, compression is worthwhile as long as it is painless and transparent. Don't bother trying to compress pre-compressed files such as jpeg, and just let mod_gzip handle the rest. You'll have to trade off the bandwidth savings against the increased CPU time and disk space consumed, adjusting the minimum filesize and the allowable gzip file 'cache' size to balance it all out for the traffic profile of your pages.

Jim

[jimbeetle]

Missed this earlier.

Here goes, everything from behind ZoneAlarm 3.7, Win 98.

IE6 Accepted encodings gzip, deflate

Opera 7.2 Accepted encodings deflate, gzip, x-gzip, identity, *;q=0

Moz 5.0 Accepted Encodings gzip,deflate,compress;q=0.9

And just downloaded update to ZoneAlarm 4.5. If somebody else doesn't get to it first I'll try to run the check tomorrow.

[jatar_k]

I happen to use an old zone alarm (Pro 2.6.357) on XP and I got

moz 1.5 gzip, deflate
ie 6 gzip, deflate

my machine is more than a little crippled right now so those are the only browsers I have.

I will try the full gamut tomorrow but that will be on the big hardware firewalls.

[mipapage]

Wow, I thought this thread was orphaned!

Thanks for the responses you three. We're looking to run some form of comression on a site we're launching soon.

Once I get some logs I'll try and post the ratio of those that accept vs. those that don't. I suppose that's what counts.

I was hoping you'd get a better response on this

Yeah, I felt a little dorky when no one responded at first!

[Alternative Future]

WindowsXP - SP1 - No Firewall installed as yet, shall report back when it gets installed soon.

Tested using :- ht*p://www.performancecorps.org/browser_check.php

USER AGENT Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030728 Mozilla Firebird/0.6.1
CONNECTION keep-alive
ACCEPTED ENCODINGS gzip,deflate
****************
USER AGENTMozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1) Opera 7.20 [en]
CONNECTIONKeep-Alive
ACCEPTED ENCODINGSdeflate, gzip, x-gzip, identity, *;q=0
****************
USER AGENT Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Alexa Toolbar)
CONNECTION Keep-Alive
ACCEPTED ENCODINGS gzip, deflate
****************

HTH,

-George

[decdim]

Off topic question?

What did you use to get the CLIENT HOSTNAME?

Here is my results:

USER AGENT Mozilla/4.0 (compatible; MSIE 6.0; Windows 98)
HTTP PROTOCOL HTTP/1.1
CONNECTION Keep-Alive
ACCEPTED ENCODINGS gzip, deflate
CLIENT IP ADDRESS <snip>
CLIENT HOSTNAME <snip>

Using Win98SE, IE 6.0.2800.1106, ZoneAlarm 3.7.211

[mipapage]

Thanks folks,

Seems like Norton is the most aggressive of the firewalls/antivirus' that do this.

The other day it actually zapped a link from a webpage that I was viewing. Others could see it, not me!

[bird]

So are you really saying that Norton filters HTTP_ACCEPT_ENCODING away from your request?

[mipapage]

Yeah, well, it turns it into that 'gibberish' that I posted in the first message.