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54 <h1 class="SECT1"><a name="TROUBLE" id="TROUBLE">5.
55 Troubleshooting</a></h1>
58 <h3 class="SECT2"><a name="AEN1100" id="AEN1100">5.1. I cannot connect
59 to any websites. Or, I am getting <span class="QUOTE">"connection
60 refused"</span> message with every web page. Why?</a></h3>
62 <p>There are several possibilities:</p>
66 <p><span class="APPLICATION">Privoxy</span> is not running.
67 Solution: verify that <span class="APPLICATION">Privoxy</span> is
68 installed correctly, has not crashed, and is indeed running. Turn
69 on <span class="APPLICATION">Privoxy's</span> logging, and look at
70 the logs to see what they say.</p>
74 <p>Or your browser is configured for a different port than what
75 <span class="APPLICATION">Privoxy</span> is using. Solution: verify
76 that <span class="APPLICATION">Privoxy</span> and your browser are
77 set to the same port (<tt class="LITERAL">listen-address</tt>).</p>
81 <p>Or if using a forwarding rule, you have a configuration problem
82 or a problem with a host in the forwarding chain. Solution:
83 temporarily alter your configuration and take the forwarders out of
88 <p>Or you have a firewall that is interfering and blocking you.
89 Solution: try disabling or removing the firewall as a simple
96 <h3 class="SECT2"><a name="ERROR503" id="ERROR503">5.2. Why am I
97 getting a 503 Error (WSAECONNREFUSED) on every page?</a></h3>
99 <p>More than likely this is a problem with your TCP/IP networking.
100 ZoneAlarm has been reported to cause this symptom -- even if not
101 running! The solution is to either fight the ZA configuration, or
102 uninstall ZoneAlarm, and then find something better behaved in its
103 place. Other personal firewall type products may cause similar type
104 problems if not configured correctly.</p>
108 <h3 class="SECT2"><a name="AEN1123" id="AEN1123">5.3. I just added a
109 new rule, but the steenkin ad is still getting through. How?</a></h3>
111 <p>If the ad had been displayed before you added its URL, it will
112 probably be held in the browser's cache for some time, so it will be
113 displayed without the need for any request to the server, and
114 <span class="APPLICATION">Privoxy</span> will not be involved. Flush
115 the browser's caches, and then try again.</p>
117 <p>If this doesn't help, you probably have an error in the rule you
118 applied. Try pasting the full URL of the offending ad into <a href=
119 "http://config.privoxy.org/show-url-info" target=
120 "_top">http://config.privoxy.org/show-url-info</a> and see if it really
121 matches your new rule. Blocking ads is like blocking spam: a lot of
122 tinkering is required to stay ahead of the game. And remember you need
123 to block the URL of the ad in question, which may be entirely different
124 from the site URL itself. Most ads are hosted on different servers than
125 the main site itself. If you right-click on the ad, you should be able
126 to get all the relevant information you need. Alternately, you can find
127 the correct URL by looking at <span class=
128 "APPLICATION">Privoxy's</span> logs (you may need to enable logging in
129 the main config file if its disabled).</p>
131 <p>Below is a slightly modified real-life log snippet that originates
132 with one requested URL: <tt class="LITERAL">www.example.com</tt> (name
133 of site was changed for this example, the number of requests is real).
134 You can see in this the complexity of what goes into making up this one
135 <span class="QUOTE">"page"</span>. There are eight different domains
136 involved here, with thirty two separate URLs requested in all, making
137 up all manner of images, Shockwave Flash, JavaScript, CSS stylesheets,
138 scripts, and other related content. Some of this content is obviously
139 <span class="QUOTE">"good"</span> or <span class="QUOTE">"bad"</span>,
140 but not all. Many of the more questionable looking requests, are going
141 to outside domains that seem to be identifying themselves with
142 suspicious looking names, making our job a little easier. <span class=
143 "APPLICATION">Privoxy</span> has <span class="QUOTE">"crunched"</span>
144 (meaning caught and BLOCKED) quite a few items in this example, but
145 perhaps missed a few as well.</p>
147 <table class="c2" border="0" width="100%">
151 Request: www.example.com/
152 Request: www.example.com/favicon.ico
153 Request: img.example.com/main.css
154 Request: img.example.com/sr.js
155 Request: example.betamarker.com/example.html
156 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
157 Request: img.example.com/pb.png
158 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
159 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
160 Request: img.example.com/p.gif
161 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
162 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
163 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
164 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
165 Request: www.adtrak.net/adx.js crunch! (Blocked)
166 Request: img.example.com/hbg.gif
167 Request: img.example.com/example.jpg
168 Request: img.example.com/mt.png
169 Request: img.example.com/mm.png
170 Request: img.example.com/mb.png
171 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
172 Request: www.example.com/tracker.js
173 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
174 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
175 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
176 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
177 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
178 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
179 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
180 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
181 Request: 66.70.21.80/img/pixel.gif
182 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
183 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
189 <p>Despite 12 out of 32 requests being blocked, the page looked, and
190 seemed to behave perfectly <span class="QUOTE">"normal"</span> (minus
191 some ads, of course).</p>
195 <h3 class="SECT2"><a name="BADSITE" id="BADSITE">5.4. One of my
196 favorite sites does not work with Privoxy. What can I do?</a></h3>
198 <p>First verify that it is indeed a <span class=
199 "APPLICATION">Privoxy</span> problem, by toggling off <span class=
200 "APPLICATION">Privoxy</span> through <a href=
201 "http://config.privoxy.org/toggle" target=
202 "_top">http://config.privoxy.org/toggle</a> (the toggle feature may
203 need to be enabled in the main <tt class="FILENAME">config</tt>), and
204 then shift-reloading the problem page (i.e. holding down the shift key
205 while clicking reload. Alternatively, flush your browser's disk and
208 <p>If the problem went away, we know we have a configuration related
209 problem. Now go to <a href="http://config.privoxy.org/show-url-info"
210 target="_top">http://config.privoxy.org/show-url-info</a> and paste the
211 full URL of the page in question into the prompt. See which actions are
212 being applied to the URL, and which matches in which actions files are
213 responsible for that. It might be helpful also to look at your logs for
214 this site too, to see what else might be happening (note: logging may
215 need to be enabled in the main config file). Many sites are complex and
216 require a number of related pages to help present their content. Look
217 at what else might be used by the page in question, and what of that
218 might be <span class="emphasis EMPHASIS c3">required</span>. Now, armed
219 with this information, go to <a href=
220 "http://config.privoxy.org/show-status" target=
221 "_top">http://config.privoxy.org/show-status</a> and select the
222 appropriate actions files for editing.</p>
224 <p>You can now either look for a section which disables the actions
225 that you suspect to cause the problem and add a pattern for your site
226 there, or make up a completely new section for your site. In any case,
227 the recommended way is to disable only the prime suspect, reload the
228 problem page, and only if the problem persists, disable more and more
229 actions until you have identified the culprit. You may or may not want
230 to turn the other actions on again. Remember to flush your browser's
231 caches in between any such changes!</p>
233 <p>Alternately, if you are comfortable with a text editor, you can
234 accomplish the same thing by editing the appropriate actions file.
235 Probably the easiest way to deal with such problems when editing by
236 hand is to add your site to a <tt class="LITERAL">{ fragile }</tt>
237 section in <tt class="FILENAME">user.action</tt>, which is an alias
238 that turns off most <span class="QUOTE">"dangerous"</span> actions, but
239 is also likely to turn off more actions then needed, and thus lower
240 your privacy and protection more than necessary,</p>
242 <p>Troubleshooting actions is discussed in more detail in the <a href=
243 "../user-manual/appendix.html#ACTIONSANAT" target="_top">User Manual
244 appendix, Troubleshooting: the Anatomy of an Action</a>. There is also
245 an <a href="../user-manual/actions-file.html#ACT-EXAMPLES" target=
246 "_top">actions tutorial</a> with general configuration information and
249 <p>As a last resort, you can always see if your browser has a setting
250 that will bypass the proxy setting for selective sites. Modern browsers
255 <h3 class="SECT2"><a name="DUN" id="DUN">5.5. After installing Privoxy,
256 I have to log in every time I start IE. What gives?</a></h3>
258 <p>This is a quirk that effects the installation of <span class=
259 "APPLICATION">Privoxy</span>, in conjunction with Internet Explorer and
260 Internet Connection Sharing on Windows 2000 and Windows XP. The
261 symptoms may appear to be corrupted or invalid DUN settings, or
264 <p>When setting up an NT based Windows system with <span class=
265 "APPLICATION">Privoxy</span> you may find that things do not seem to be
266 doing what you expect. When you set your system up you will probably
267 have set up Internet Connection Sharing (ICS) with Dial up Networking
268 (DUN) when logged in with administrator privileges. You will probably
269 have made this DUN connection available to other accounts that you may
270 have set-up on your system. E.g. Mum or Dad sets up the system and
271 makes accounts suitably configured for the kids.</p>
273 <p>When setting up <span class="APPLICATION">Privoxy</span> in this
274 environment you will have to alter the proxy set-up of Internet
275 Explorer (IE) for the specific DUN connection on which you wish to use
276 <span class="APPLICATION">Privoxy</span>. When you do this the ICS DUN
277 set-up becomes user specific. In this instance you will see no
278 difference if you change the DUN connection under the account used to
279 set-up the connection. However when you do this from another user you
280 will notice that the DUN connection changes to make available to "Me
281 only". You will also find that you have to store the password under
282 each different user!</p>
284 <p>The reason for this is that each user's set-up for IE is user
285 specific. Each set-up DUN connection and each LAN connection in IE
286 store the settings for each user individually. As such this enforces
287 individual configurations rather than common ones. Hence the first time
288 you use a DUN connection after re-booting your system it may not
289 perform as you expect, and prompt you for the password. Just set and
290 save the password again and all should be OK.</p>
292 <p>[Thanks to Ray Griffith for this submission.]</p>
296 <h3 class="SECT2"><a name="FTP" id="FTP">5.6. I cannot connect to any
297 FTP sites. Privoxy is blocking me.</a></h3>
299 <p><span class="APPLICATION">Privoxy</span> cannot act as a proxy for
300 FTP traffic, so do not configure your browser to use <span class=
301 "APPLICATION">Privoxy</span> as an FTP proxy. The same is true for
302 <span class="emphasis EMPHASIS c3">any protocol other than HTTP or
303 HTTPS (SSL)</span>.</p>
305 <p>Most browsers understand FTP as well as HTTP. If you connect to a
306 site, with a URL like <tt class="LITERAL">ftp://ftp.example.com</tt>,
307 your browser is making an FTP connection, and not a HTTP connection. So
308 while your browser may speak FTP, <span class=
309 "APPLICATION">Privoxy</span> does not, and cannot proxy such
312 <p>To complicate matters, some systems may have a generic <span class=
313 "QUOTE">"proxy"</span> setting, which will enable various protocols,
314 including <span class="emphasis EMPHASIS c3">both</span> HTTP and FTP
315 proxying! So it is possible to accidentally enable FTP proxying in
316 these cases. And of course, if this happens, <span class=
317 "APPLICATION">Privoxy</span> will indeed cause problems since it does
318 not know FTP. Newer version will give a sane error message if a FTP
319 connection is attempted. Just disable the FTP setting and all will be
322 <p>Will <span class="APPLICATION">Privoxy</span> ever proxy FTP
323 traffic? Unlikely. There just is not much reason, and the work to make
324 this happen is more than it may seem.</p>
328 <h3 class="SECT2"><a name="MACOSXIE" id="MACOSXIE">5.7. In Mac OS X, I
329 can't configure Microsoft Internet Explorer to use Privoxy as the HTTP
332 <p>Microsoft Internet Explorer (in versions like 5.1) respects
333 system-wide network settings. In order to change the HTTP proxy, open
334 System Preferences, and click on the Network icon. In the settings pane
335 that comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)"
336 checkbox is checked and enter <tt class="LITERAL">127.0.0.1</tt> in the
337 entry field. Enter <tt class="LITERAL">8118</tt> in the Port field. The
338 next time you start IE, it should reflect these values.</p>
342 <h3 class="SECT2"><a name="MACOSXUNINSTALL" id="MACOSXUNINSTALL">5.8.
343 In Mac OS X, I dragged the Privoxy folder to the trash in order to
344 uninstall it. Now the finder tells me I don't have sufficient
345 privileges to empty the trash.</a></h3>
347 <p>Note: This ONLY applies to privoxy 3.0.6 and earlier.</p>
349 <p>Just dragging the <span class="APPLICATION">Privoxy</span> folder to
350 the trash is not enough to delete it. <span class=
351 "APPLICATION">Privoxy</span> supplies an <span class=
352 "APPLICATION">uninstall.command</span> file that takes care of these
353 details. Open the trash, drag the <span class=
354 "APPLICATION">uninstall.command</span> file out of the trash and
355 double-click on it. You will be prompted for confirmation and the
356 administration password.</p>
358 <p>The trash may still appear full after this command; emptying the
359 trash from the desktop should make it appear empty again.</p>
363 <h3 class="SECT2"><a name="MACOSXIMAGES" id="MACOSXIMAGES">5.9. In Mac
364 OS X Panther (10.3), images often fail to load and/or I experience
365 random delays in page loading. I'm using <tt class=
366 "LITERAL">localhost</tt> as my browser's proxy setting.</a></h3>
368 <p>We believe this is due to an IPv6-related bug in Mac OS X, but don't
369 fully understand the issue yet. In any case, changing the proxy setting
370 to <tt class="LITERAL">127.0.0.1</tt> instead of <tt class=
371 "LITERAL">localhost</tt> works around the problem.</p>
375 <h3 class="SECT2"><a name="BLANKPAGE" id="BLANKPAGE">5.10. I get a
376 completely blank page at one site. <span class="QUOTE">"View
377 Source"</span> shows only: <span class=
378 "MARKUP"><html><body></body></html></span>.
379 Without Privoxy the page loads fine.</a></h3>
381 <p>Chances are that the site suffers from a bug in <a href=
382 "http://www.php.net/" target="_top"><span class=
383 "APPLICATION">PHP</span></a>, which results in empty pages being sent
384 if the client explicitly requests an uncompressed page, like
385 <span class="APPLICATION">Privoxy</span> does. This bug has been fixed
388 <p>To find out if this is in fact the source of the problem, try adding
389 the site to a <tt class="LITERAL">-prevent-compression</tt> section in
390 <tt class="FILENAME">user.action</tt>:</p>
392 <table class="c2" border="0" width="100%">
396 # Make exceptions for ill-behaved sites:
398 {-prevent-compression}
405 <p>If that works, you may also want to report the problem to the site's
406 webmasters, telling them to use zlib.output_compression instead of
407 ob_gzhandler in their PHP applications (workaround) or upgrade to PHP
408 4.2.3 or later (fix).</p>
412 <h3 class="SECT2"><a name="NOHOSTNAME" id="NOHOSTNAME">5.11. My logs
413 show many <span class="QUOTE">"Unable to get my own hostname"</span>
416 <p><span class="APPLICATION">Privoxy</span> tries to get the hostname
417 of the system its running on from the IP address of the system
418 interface it is bound to (from the <tt class="FILENAME">config</tt>
419 file <span class="emphasis EMPHASIS c3">listen-address</span> setting).
420 If the system cannot supply this information, <span class=
421 "APPLICATION">Privoxy</span> logs this condition.</p>
423 <p>Typically, this would be considered a minor system configuration
424 error. It is not a fatal error to <span class=
425 "APPLICATION">Privoxy</span> however, but may result in a much slower
426 response from <span class="APPLICATION">Privoxy</span> on some
427 platforms due to DNS timeouts.</p>
429 <p>This can be caused by a problem with the local <tt class=
430 "FILENAME">hosts</tt> file. If this file has been changed from the
431 original, try reverting it to see if that helps. Make sure whatever
432 name(s) are used for the local system, that they resolve both ways.</p>
434 <p>You should also be able to work around the problem with the <a href=
435 "../user-manual/config.html#HOSTNAME" target="_top">hostname
440 <h3 class="SECT2"><a name="INUSE" id="INUSE">5.12. When I try to launch
441 Privoxy, I get an error message <span class="QUOTE">"port 8118 is
442 already in use"</span> (or similar wording). Why?</a></h3>
444 <p>Port 8118 is <span class="APPLICATION">Privoxy's</span> default TCP
445 <span class="QUOTE">"listening"</span> port. Typically this message
446 would mean that there is already one instance of <span class=
447 "APPLICATION">Privoxy</span> running, and your system is actually
448 trying to start a second <span class="APPLICATION">Privoxy</span> on
449 the same port, which will not work. (You can have multiple instances
450 but they must be assigned different ports.) How and why this might
451 happen varies from platform to platform, but you need to check your
452 installation and start-up procedures.</p>
456 <h3 class="SECT2"><a name="DEMORONIZER" id="DEMORONIZER">5.13. Pages
457 with UTF-8 fonts are garbled.</a></h3>
459 <p>This is caused by the <span class="QUOTE">"demoronizer"</span>
460 filter. You should either upgrade <span class=
461 "APPLICATION">Privoxy</span>, or at least upgrade to the most recent
462 <tt class="FILENAME">default.action</tt> file available from <a href=
463 "http://sourceforge.net/project/showfiles.php?group_id=11118" target=
464 "_top">SourceForge</a>. Or you can simply disable the demoronizer
469 <h3 class="SECT2"><a name="DEMORONIZER2" id="DEMORONIZER2">5.14. Why
470 are binary files (such as images) corrupted when Privoxy is
473 <p>This may also be caused by the <span class=
474 "QUOTE">"demoronizer"</span> filter, in conjunction with a web server
475 that is misreporting the content type. Binary files are exempted from
476 <span class="APPLICATION">Privoxy's</span> filtering (unless the web
477 server by mistake says the file is something else). Either upgrade
478 <span class="APPLICATION">Privoxy</span>, or go to the most recent
479 <tt class="FILENAME">default.action</tt> file available from <a href=
480 "http://sourceforge.net/project/showfiles.php?group_id=11118" target=
481 "_top">SourceForge</a>.</p>
485 <h3 class="SECT2"><a name="DEMORONIZER3" id="DEMORONIZER3">5.15. What
486 is the <span class="QUOTE">"demoronizer"</span> and why is it
489 <p>The original demoronizer was a Perl script that cleaned up HTML
490 pages which were created with certain Microsoft products. MS has used
491 proprietary extensions to standardized font encodings (ISO 8859-1),
492 which has caused problems for pages that are viewed with non-Microsoft
493 products (and are expecting to see a standard set of fonts). The
494 demoronizer corrected these errors so the pages displayed correctly.
495 <span class="APPLICATION">Privoxy</span> borrowed from this script,
496 introducing a filter based on the original demoronizer, which in turn
497 could correct these errors on the fly.</p>
499 <p>But this is only needed in some situations, and will cause serious
500 problems in some other situations.</p>
502 <p>If you are using Microsoft products, you do not need it. If you need
503 to view pages with UTF-8 characters (such as Cyrillic or Chinese), then
504 it will cause corruption of the fonts, and thus <span class=
505 "emphasis EMPHASIS c3">should not be on</span>.</p>
507 <p>On the other hand, if you use non-Microsoft products, and you
508 occasionally notice weird characters on pages, you might want to try
513 <h3 class="SECT2"><a name="WINDOWOPEN" id="WINDOWOPEN">5.16. Why do I
514 keep seeing <span class="QUOTE">"PrivoxyWindowOpen()"</span> in raw
515 source code?</a></h3>
517 <p><span class="APPLICATION">Privoxy</span> is attempting to disable
518 malicious <a href="http://en.wikipedia.org/wiki/Javascript" target=
519 "_top">Javascript</a> in this case, with the <tt class=
520 "LITERAL">unsolicited-popups</tt> filter. <span class=
521 "APPLICATION">Privoxy</span> cannot tell very well <span class=
522 "QUOTE">"good"</span> code snippets from <span class=
523 "QUOTE">"bad"</span> code snippets.</p>
525 <p>If you see this in HTML source, and the page displays without
526 problems, then this is good, and likely some pop-up window was
527 disabled. If you see this where it is causing a problem, such as a
528 downloaded program source code file, then you should set an exception
529 for this site or page such that the integrity of the page stays in tact
530 by disabling all filtering.</p>
534 <h3 class="SECT2"><a name="DNSERRORS" id="DNSERRORS">5.17. I am getting
535 too many DNS errors like <span class="QUOTE">"404 No Such
536 Domain"</span>. Why can't Privoxy do this better?</a></h3>
538 <p>There are potentially several factors here. First of all, the DNS
539 resolution is done by the underlying operating system -- not
540 <span class="APPLICATION">Privoxy</span> itself. <span class=
541 "APPLICATION">Privoxy</span> merely initiates the process and hands it
542 off, and then later reports whatever the outcome was and tries to give
543 a coherent message if there seems to be a problem. In some cases, this
544 might otherwise be mitigated by the browser itself which might try some
545 work-arounds and alternate approaches (e.g adding <span class=
546 "QUOTE">"www."</span> to the URL).</p>
548 <p>In other cases, if <span class="APPLICATION">Privoxy</span> is being
549 chained with another proxy, this could complicate the issue, and cause
550 undue delays and timeouts. In the case of a <span class=
551 "QUOTE">"socks4a"</span> proxy, the socks server handles all the DNS.
552 <span class="APPLICATION">Privoxy</span> would just be the <span class=
553 "QUOTE">"messenger"</span> which is reporting whatever problem occurred
554 downstream, and not the root cause of the error.</p>
556 <p>In any case, versions newer than 3.0.3 include various improvements
557 to help <span class="APPLICATION">Privoxy</span> better handle these
562 <h3 class="SECT2"><a name="ALLCPU" id="ALLCPU">5.18. At one site
563 Privoxy just hangs, and starts taking all CPU. Why is this?</a></h3>
565 <p>This is probably a manifestation of the <span class="QUOTE">"100%
566 cpu"</span> problem that occurs on pages containing many (thousands
567 upon thousands) of blank lines. The blank lines are in the raw HTML
568 source of the page, and the browser just ignores them. But the pattern
569 matching in <span class="APPLICATION">Privoxy's</span> page filtering
570 mechanism is trying to match against absurdly long strings and this
571 becomes very CPU-intensive, taking a long, long time to complete.</p>
573 <p>Until a better solution comes along, disable filtering on these
574 pages, particularly the <tt class="LITERAL">js-annoyances</tt> and
575 <tt class="LITERAL">unsolicited-popups</tt> filters. If you run into
576 this problem with a recent <span class="APPLICATION">Privoxy</span>
577 version, please send a problem report.</p>
581 <h3 class="SECT2"><a name="SLOWCRAWL" id="SLOWCRAWL">5.19. I just
582 installed Privoxy, and all my browsing has slowed to a crawl. What
585 <p>This should not happen, and for the overwhelming number of users
586 world-wide, it does not happen. I would suspect some inadvertent
587 interaction of software components such as anti-virus software, spyware
588 protectors, personal firewalls or similar components. Try disabling (or
589 uninstalling) these one at a time and see if that helps. Either way, if
590 you are using a recent <span class="APPLICATION">Privoxy</span>
591 version, please report the problem.</p>
595 <h3 class="SECT2"><a name="PREVENTCOMP" id="PREVENTCOMP">5.20. Why do
596 my filters work on some sites but not on others?</a></h3>
598 <p>It's probably due to compression. It is a common practice for web
599 servers to send their content <span class="QUOTE">"compressed"</span>
600 in order to speed things up, and then let the browser <span class=
601 "QUOTE">"uncompress"</span> them. When compiled with zlib support
602 <span class="APPLICATION">Privoxy</span> can decompress content before
603 filtering, otherwise you may want to enable <a href=
604 "../user-manual/actions-file.html#PREVENT-COMPRESSION" target=
605 "_top">prevent-compression</a>.</p>
607 <p>As of <span class="APPLICATION">Privoxy</span> 3.0.9, zlib support
608 is enabled in the default builds.</p>
612 <h3 class="SECT2"><a name="SSL-WARNINGS" id="SSL-WARNINGS">5.21. On
613 some HTTPS sites my browser warns me about unauthenticated content, the
614 URL bar doesn't get highlighted and the lock symbol appears to be
615 broken. What's going on?</a></h3>
617 <p>Probably the browser is requesting ads through HTTPS and
618 <span class="APPLICATION">Privoxy</span> is blocking the requests.
619 Privoxy's error messages are delivered unencrypted and while it's
620 obvious for the browser that the HTTPS request is already blocked by
621 the proxy, some warn about unauthenticated content anyway.</p>
623 <p>To work around the problem you can redirect those requests to an
624 invalid local address instead of blocking them. While the redirects
625 aren't encrypted either, many browsers don't care. They simply follow
626 the redirect, fail to reach a server and display an error message
627 instead of the ad.</p>
629 <p>To do that, enable logging to figure out which requests get blocked
630 by <span class="APPLICATION">Privoxy</span> and add the hosts (no path
631 patterns) to a section like this:</p>
633 <table class="c2" border="0" width="100%">
637 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
644 <p>Additionally you have to configure your browser to contact
645 <span class="QUOTE">"127.0.0.1:0"</span> directly (instead of through
646 <span class="APPLICATION">Privoxy</span>).</p>
648 <p>To add a proxy exception in <span class="APPLICATION">Mozilla
649 Firefox</span> open the <span class="QUOTE">"Preferences"</span>, click
650 the <span class="QUOTE">"Settings"</span> button located on the
651 <span class="QUOTE">"Network"</span> tab in the <span class=
652 "QUOTE">"Advanced"</span> section, and add <span class=
653 "QUOTE">"127.0.0.1:0"</span> in the <span class="QUOTE">"No Proxy
654 for:"</span> field.</p>
658 <h3 class="SECT2"><a name="SE-LINUX" id="SE-LINUX">5.22. I get selinux
659 error messages. How can I fix this?</a></h3>
661 <p>Please report the problem to the creator of your selinux
664 <p>The problem is that some selinux policy writers aren't familiar with
665 the application they are trying to <span class="QUOTE">"secure"</span>
666 and thus create policies that make no sense.</p>
668 <p>In <span class="APPLICATION">Privoxy's</span> case the problem
669 usually is that the policy only allows outgoing connections for certain
670 destination ports (e.g. 80 and 443). While this may cover the standard
671 ports, websites occasionally use other ports as well. This isn't a
672 security problem and therefore <span class=
673 "APPLICATION">Privoxy's</span> default configuration doesn't block
676 <p>If you really want to block these ports (and don't be able to load
677 websites that don't use standard ports), you should configure Privoxy
678 to block these ports as well, so it doesn't trigger the selinux
683 <h3 class="SECT2"><a name="GENTOO-RICERS" id="GENTOO-RICERS">5.23. I
684 compiled <span class="APPLICATION">Privoxy</span> with Gentoo's portage
685 and it appears to be very slow. Why?</a></h3>
687 <p>Probably you unintentionally compiled <span class=
688 "APPLICATION">Privoxy</span> without threading support in which case
689 requests have to be serialized and only one can be served at the same
692 <p>Check your <span class="QUOTE">"USE"</span> flags and make sure they
693 include <span class="QUOTE">"threads"</span>. If they don't, add the
694 flag and rebuild <span class="APPLICATION">Privoxy</span>.</p>
696 <p>If you compiled <span class="APPLICATION">Privoxy</span> with
697 threading support (on POSIX-based systems), the <span class=
698 "QUOTE">"Conditional #defines"</span> section on <a href=
699 "http://config.privoxy.org/show-status" target=
700 "_top">http://config.privoxy.org/show-status</a> will list <span class=
701 "QUOTE">"FEATURE_PTHREAD"</span> as <span class=
702 "QUOTE">"enabled"</span>.</p>
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