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57 <h1 class="SECT1"><a name="TROUBLE" id="TROUBLE">5.
58 Troubleshooting</a></h1>
61 <h3 class="SECT2"><a name="AEN1100" id="AEN1100">5.1. I cannot connect
62 to any websites. Or, I am getting <span class="QUOTE">"connection
63 refused"</span> message with every web page. Why?</a></h3>
65 <p>There are several possibilities:</p>
69 <p><span class="APPLICATION">Privoxy</span> is not running.
70 Solution: verify that <span class="APPLICATION">Privoxy</span> is
71 installed correctly, has not crashed, and is indeed running. Turn
72 on <span class="APPLICATION">Privoxy's</span> logging, and look at
73 the logs to see what they say.</p>
77 <p>Or your browser is configured for a different port than what
78 <span class="APPLICATION">Privoxy</span> is using. Solution: verify
79 that <span class="APPLICATION">Privoxy</span> and your browser are
80 set to the same port (<tt class="LITERAL">listen-address</tt>).</p>
84 <p>Or if using a forwarding rule, you have a configuration problem
85 or a problem with a host in the forwarding chain. Solution:
86 temporarily alter your configuration and take the forwarders out of
91 <p>Or you have a firewall that is interfering and blocking you.
92 Solution: try disabling or removing the firewall as a simple
99 <h3 class="SECT2"><a name="ERROR503" id="ERROR503">5.2. Why am I
100 getting a 503 Error (WSAECONNREFUSED) on every page?</a></h3>
102 <p>More than likely this is a problem with your TCP/IP networking.
103 ZoneAlarm has been reported to cause this symptom -- even if not
104 running! The solution is to either fight the ZA configuration, or
105 uninstall ZoneAlarm, and then find something better behaved in its
106 place. Other personal firewall type products may cause similar type
107 problems if not configured correctly.</p>
111 <h3 class="SECT2"><a name="AEN1123" id="AEN1123">5.3. I just added a
112 new rule, but the steenkin ad is still getting through. How?</a></h3>
114 <p>If the ad had been displayed before you added its URL, it will
115 probably be held in the browser's cache for some time, so it will be
116 displayed without the need for any request to the server, and
117 <span class="APPLICATION">Privoxy</span> will not be involved. Flush
118 the browser's caches, and then try again.</p>
120 <p>If this doesn't help, you probably have an error in the rule you
121 applied. Try pasting the full URL of the offending ad into <a href=
122 "http://config.privoxy.org/show-url-info" target=
123 "_top">http://config.privoxy.org/show-url-info</a> and see if it really
124 matches your new rule. Blocking ads is like blocking spam: a lot of
125 tinkering is required to stay ahead of the game. And remember you need
126 to block the URL of the ad in question, which may be entirely different
127 from the site URL itself. Most ads are hosted on different servers than
128 the main site itself. If you right-click on the ad, you should be able
129 to get all the relevant information you need. Alternately, you can find
130 the correct URL by looking at <span class=
131 "APPLICATION">Privoxy's</span> logs (you may need to enable logging in
132 the main config file if its disabled).</p>
134 <p>Below is a slightly modified real-life log snippet that originates
135 with one requested URL: <tt class="LITERAL">www.example.com</tt> (name
136 of site was changed for this example, the number of requests is real).
137 You can see in this the complexity of what goes into making up this one
138 <span class="QUOTE">"page"</span>. There are eight different domains
139 involved here, with thirty two separate URLs requested in all, making
140 up all manner of images, Shockwave Flash, JavaScript, CSS stylesheets,
141 scripts, and other related content. Some of this content is obviously
142 <span class="QUOTE">"good"</span> or <span class="QUOTE">"bad"</span>,
143 but not all. Many of the more questionable looking requests, are going
144 to outside domains that seem to be identifying themselves with
145 suspicious looking names, making our job a little easier. <span class=
146 "APPLICATION">Privoxy</span> has <span class="QUOTE">"crunched"</span>
147 (meaning caught and BLOCKED) quite a few items in this example, but
148 perhaps missed a few as well.</p>
150 <table class="c2" border="0" width="100%">
154 Request: www.example.com/
155 Request: www.example.com/favicon.ico
156 Request: img.example.com/main.css
157 Request: img.example.com/sr.js
158 Request: example.betamarker.com/example.html
159 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
160 Request: img.example.com/pb.png
161 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
162 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
163 Request: img.example.com/p.gif
164 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
165 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
166 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
167 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
168 Request: www.adtrak.net/adx.js crunch! (Blocked)
169 Request: img.example.com/hbg.gif
170 Request: img.example.com/example.jpg
171 Request: img.example.com/mt.png
172 Request: img.example.com/mm.png
173 Request: img.example.com/mb.png
174 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
175 Request: www.example.com/tracker.js
176 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
177 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
178 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
179 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
180 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
181 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
182 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
183 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
184 Request: 66.70.21.80/img/pixel.gif
185 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
186 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
192 <p>Despite 12 out of 32 requests being blocked, the page looked, and
193 seemed to behave perfectly <span class="QUOTE">"normal"</span> (minus
194 some ads, of course).</p>
198 <h3 class="SECT2"><a name="BADSITE" id="BADSITE">5.4. One of my
199 favorite sites does not work with Privoxy. What can I do?</a></h3>
201 <p>First verify that it is indeed a <span class=
202 "APPLICATION">Privoxy</span> problem, by toggling off <span class=
203 "APPLICATION">Privoxy</span> through <a href=
204 "http://config.privoxy.org/toggle" target=
205 "_top">http://config.privoxy.org/toggle</a> (the toggle feature may
206 need to be enabled in the main <tt class="FILENAME">config</tt>), and
207 then shift-reloading the problem page (i.e. holding down the shift key
208 while clicking reload. Alternatively, flush your browser's disk and
211 <p>If the problem went away, we know we have a configuration related
212 problem. Now go to <a href="http://config.privoxy.org/show-url-info"
213 target="_top">http://config.privoxy.org/show-url-info</a> and paste the
214 full URL of the page in question into the prompt. See which actions are
215 being applied to the URL, and which matches in which actions files are
216 responsible for that. It might be helpful also to look at your logs for
217 this site too, to see what else might be happening (note: logging may
218 need to be enabled in the main config file). Many sites are complex and
219 require a number of related pages to help present their content. Look
220 at what else might be used by the page in question, and what of that
221 might be <span class="emphasis EMPHASIS c3">required</span>. Now, armed
222 with this information, go to <a href=
223 "http://config.privoxy.org/show-status" target=
224 "_top">http://config.privoxy.org/show-status</a> and select the
225 appropriate actions files for editing.</p>
227 <p>You can now either look for a section which disables the actions
228 that you suspect to cause the problem and add a pattern for your site
229 there, or make up a completely new section for your site. In any case,
230 the recommended way is to disable only the prime suspect, reload the
231 problem page, and only if the problem persists, disable more and more
232 actions until you have identified the culprit. You may or may not want
233 to turn the other actions on again. Remember to flush your browser's
234 caches in between any such changes!</p>
236 <p>Alternately, if you are comfortable with a text editor, you can
237 accomplish the same thing by editing the appropriate actions file.
238 Probably the easiest way to deal with such problems when editing by
239 hand is to add your site to a <tt class="LITERAL">{ fragile }</tt>
240 section in <tt class="FILENAME">user.action</tt>, which is an alias
241 that turns off most <span class="QUOTE">"dangerous"</span> actions, but
242 is also likely to turn off more actions then needed, and thus lower
243 your privacy and protection more than necessary,</p>
245 <p>Troubleshooting actions is discussed in more detail in the <a href=
246 "../user-manual/appendix.html#ACTIONSANAT" target="_top">User Manual
247 appendix, Troubleshooting: the Anatomy of an Action</a>. There is also
248 an <a href="../user-manual/actions-file.html#ACT-EXAMPLES" target=
249 "_top">actions tutorial</a> with general configuration information and
252 <p>As a last resort, you can always see if your browser has a setting
253 that will bypass the proxy setting for selective sites. Modern browsers
258 <h3 class="SECT2"><a name="DUN" id="DUN">5.5. After installing Privoxy,
259 I have to log in every time I start IE. What gives?</a></h3>
261 <p>This is a quirk that effects the installation of <span class=
262 "APPLICATION">Privoxy</span>, in conjunction with Internet Explorer and
263 Internet Connection Sharing on Windows 2000 and Windows XP. The
264 symptoms may appear to be corrupted or invalid DUN settings, or
267 <p>When setting up an NT based Windows system with <span class=
268 "APPLICATION">Privoxy</span> you may find that things do not seem to be
269 doing what you expect. When you set your system up you will probably
270 have set up Internet Connection Sharing (ICS) with Dial up Networking
271 (DUN) when logged in with administrator privileges. You will probably
272 have made this DUN connection available to other accounts that you may
273 have set-up on your system. E.g. Mum or Dad sets up the system and
274 makes accounts suitably configured for the kids.</p>
276 <p>When setting up <span class="APPLICATION">Privoxy</span> in this
277 environment you will have to alter the proxy set-up of Internet
278 Explorer (IE) for the specific DUN connection on which you wish to use
279 <span class="APPLICATION">Privoxy</span>. When you do this the ICS DUN
280 set-up becomes user specific. In this instance you will see no
281 difference if you change the DUN connection under the account used to
282 set-up the connection. However when you do this from another user you
283 will notice that the DUN connection changes to make available to "Me
284 only". You will also find that you have to store the password under
285 each different user!</p>
287 <p>The reason for this is that each user's set-up for IE is user
288 specific. Each set-up DUN connection and each LAN connection in IE
289 store the settings for each user individually. As such this enforces
290 individual configurations rather than common ones. Hence the first time
291 you use a DUN connection after re-booting your system it may not
292 perform as you expect, and prompt you for the password. Just set and
293 save the password again and all should be OK.</p>
295 <p>[Thanks to Ray Griffith for this submission.]</p>
299 <h3 class="SECT2"><a name="FTP" id="FTP">5.6. I cannot connect to any
300 FTP sites. Privoxy is blocking me.</a></h3>
302 <p><span class="APPLICATION">Privoxy</span> cannot act as a proxy for
303 FTP traffic, so do not configure your browser to use <span class=
304 "APPLICATION">Privoxy</span> as an FTP proxy. The same is true for
305 <span class="emphasis EMPHASIS c3">any protocol other than HTTP or
306 HTTPS (SSL)</span>.</p>
308 <p>Most browsers understand FTP as well as HTTP. If you connect to a
309 site, with a URL like <tt class="LITERAL">ftp://ftp.example.com</tt>,
310 your browser is making an FTP connection, and not a HTTP connection. So
311 while your browser may speak FTP, <span class=
312 "APPLICATION">Privoxy</span> does not, and cannot proxy such
315 <p>To complicate matters, some systems may have a generic <span class=
316 "QUOTE">"proxy"</span> setting, which will enable various protocols,
317 including <span class="emphasis EMPHASIS c3">both</span> HTTP and FTP
318 proxying! So it is possible to accidentally enable FTP proxying in
319 these cases. And of course, if this happens, <span class=
320 "APPLICATION">Privoxy</span> will indeed cause problems since it does
321 not know FTP. Newer version will give a sane error message if a FTP
322 connection is attempted. Just disable the FTP setting and all will be
325 <p>Will <span class="APPLICATION">Privoxy</span> ever proxy FTP
326 traffic? Unlikely. There just is not much reason, and the work to make
327 this happen is more than it may seem.</p>
331 <h3 class="SECT2"><a name="MACOSXIE" id="MACOSXIE">5.7. In Mac OS X, I
332 can't configure Microsoft Internet Explorer to use Privoxy as the HTTP
335 <p>Microsoft Internet Explorer (in versions like 5.1) respects
336 system-wide network settings. In order to change the HTTP proxy, open
337 System Preferences, and click on the Network icon. In the settings pane
338 that comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)"
339 checkbox is checked and enter <tt class="LITERAL">127.0.0.1</tt> in the
340 entry field. Enter <tt class="LITERAL">8118</tt> in the Port field. The
341 next time you start IE, it should reflect these values.</p>
345 <h3 class="SECT2"><a name="MACOSXUNINSTALL" id="MACOSXUNINSTALL">5.8.
346 In Mac OS X, I dragged the Privoxy folder to the trash in order to
347 uninstall it. Now the finder tells me I don't have sufficient
348 privileges to empty the trash.</a></h3>
350 <p>Note: This ONLY applies to privoxy 3.0.6 and earlier.</p>
352 <p>Just dragging the <span class="APPLICATION">Privoxy</span> folder to
353 the trash is not enough to delete it. <span class=
354 "APPLICATION">Privoxy</span> supplies an <span class=
355 "APPLICATION">uninstall.command</span> file that takes care of these
356 details. Open the trash, drag the <span class=
357 "APPLICATION">uninstall.command</span> file out of the trash and
358 double-click on it. You will be prompted for confirmation and the
359 administration password.</p>
361 <p>The trash may still appear full after this command; emptying the
362 trash from the desktop should make it appear empty again.</p>
366 <h3 class="SECT2"><a name="MACOSXIMAGES" id="MACOSXIMAGES">5.9. In Mac
367 OS X Panther (10.3), images often fail to load and/or I experience
368 random delays in page loading. I'm using <tt class=
369 "LITERAL">localhost</tt> as my browser's proxy setting.</a></h3>
371 <p>We believe this is due to an IPv6-related bug in Mac OS X, but don't
372 fully understand the issue yet. In any case, changing the proxy setting
373 to <tt class="LITERAL">127.0.0.1</tt> instead of <tt class=
374 "LITERAL">localhost</tt> works around the problem.</p>
378 <h3 class="SECT2"><a name="BLANKPAGE" id="BLANKPAGE">5.10. I get a
379 completely blank page at one site. <span class="QUOTE">"View
380 Source"</span> shows only: <span class=
381 "MARKUP"><html><body></body></html></span>.
382 Without Privoxy the page loads fine.</a></h3>
384 <p>Chances are that the site suffers from a bug in <a href=
385 "http://www.php.net/" target="_top"><span class=
386 "APPLICATION">PHP</span></a>, which results in empty pages being sent
387 if the client explicitly requests an uncompressed page, like
388 <span class="APPLICATION">Privoxy</span> does. This bug has been fixed
391 <p>To find out if this is in fact the source of the problem, try adding
392 the site to a <tt class="LITERAL">-prevent-compression</tt> section in
393 <tt class="FILENAME">user.action</tt>:</p>
395 <table class="c2" border="0" width="100%">
399 # Make exceptions for ill-behaved sites:
401 {-prevent-compression}
408 <p>If that works, you may also want to report the problem to the site's
409 webmasters, telling them to use zlib.output_compression instead of
410 ob_gzhandler in their PHP applications (workaround) or upgrade to PHP
411 4.2.3 or later (fix).</p>
415 <h3 class="SECT2"><a name="NOHOSTNAME" id="NOHOSTNAME">5.11. My logs
416 show many <span class="QUOTE">"Unable to get my own hostname"</span>
419 <p><span class="APPLICATION">Privoxy</span> tries to get the hostname
420 of the system its running on from the IP address of the system
421 interface it is bound to (from the <tt class="FILENAME">config</tt>
422 file <span class="emphasis EMPHASIS c3">listen-address</span> setting).
423 If the system cannot supply this information, <span class=
424 "APPLICATION">Privoxy</span> logs this condition.</p>
426 <p>Typically, this would be considered a minor system configuration
427 error. It is not a fatal error to <span class=
428 "APPLICATION">Privoxy</span> however, but may result in a much slower
429 response from <span class="APPLICATION">Privoxy</span> on some
430 platforms due to DNS timeouts.</p>
432 <p>This can be caused by a problem with the local <tt class=
433 "FILENAME">hosts</tt> file. If this file has been changed from the
434 original, try reverting it to see if that helps. Make sure whatever
435 name(s) are used for the local system, that they resolve both ways.</p>
437 <p>You should also be able to work around the problem with the <a href=
438 "../user-manual/config.html#HOSTNAME" target="_top">hostname
443 <h3 class="SECT2"><a name="INUSE" id="INUSE">5.12. When I try to launch
444 Privoxy, I get an error message <span class="QUOTE">"port 8118 is
445 already in use"</span> (or similar wording). Why?</a></h3>
447 <p>Port 8118 is <span class="APPLICATION">Privoxy's</span> default TCP
448 <span class="QUOTE">"listening"</span> port. Typically this message
449 would mean that there is already one instance of <span class=
450 "APPLICATION">Privoxy</span> running, and your system is actually
451 trying to start a second <span class="APPLICATION">Privoxy</span> on
452 the same port, which will not work. (You can have multiple instances
453 but they must be assigned different ports.) How and why this might
454 happen varies from platform to platform, but you need to check your
455 installation and start-up procedures.</p>
459 <h3 class="SECT2"><a name="DEMORONIZER" id="DEMORONIZER">5.13. Pages
460 with UTF-8 fonts are garbled.</a></h3>
462 <p>This is caused by the <span class="QUOTE">"demoronizer"</span>
463 filter. You should either upgrade <span class=
464 "APPLICATION">Privoxy</span>, or at least upgrade to the most recent
465 <tt class="FILENAME">default.action</tt> file available from <a href=
466 "http://sourceforge.net/project/showfiles.php?group_id=11118" target=
467 "_top">SourceForge</a>. Or you can simply disable the demoronizer
472 <h3 class="SECT2"><a name="DEMORONIZER2" id="DEMORONIZER2">5.14. Why
473 are binary files (such as images) corrupted when Privoxy is
476 <p>This may also be caused by the <span class=
477 "QUOTE">"demoronizer"</span> filter, in conjunction with a web server
478 that is misreporting the content type. Binary files are exempted from
479 <span class="APPLICATION">Privoxy's</span> filtering (unless the web
480 server by mistake says the file is something else). Either upgrade
481 <span class="APPLICATION">Privoxy</span>, or go to the most recent
482 <tt class="FILENAME">default.action</tt> file available from <a href=
483 "http://sourceforge.net/project/showfiles.php?group_id=11118" target=
484 "_top">SourceForge</a>.</p>
488 <h3 class="SECT2"><a name="DEMORONIZER3" id="DEMORONIZER3">5.15. What
489 is the <span class="QUOTE">"demoronizer"</span> and why is it
492 <p>The original demoronizer was a Perl script that cleaned up HTML
493 pages which were created with certain Microsoft products. MS has used
494 proprietary extensions to standardized font encodings (ISO 8859-1),
495 which has caused problems for pages that are viewed with non-Microsoft
496 products (and are expecting to see a standard set of fonts). The
497 demoronizer corrected these errors so the pages displayed correctly.
498 <span class="APPLICATION">Privoxy</span> borrowed from this script,
499 introducing a filter based on the original demoronizer, which in turn
500 could correct these errors on the fly.</p>
502 <p>But this is only needed in some situations, and will cause serious
503 problems in some other situations.</p>
505 <p>If you are using Microsoft products, you do not need it. If you need
506 to view pages with UTF-8 characters (such as Cyrillic or Chinese), then
507 it will cause corruption of the fonts, and thus <span class=
508 "emphasis EMPHASIS c3">should not be on</span>.</p>
510 <p>On the other hand, if you use non-Microsoft products, and you
511 occasionally notice weird characters on pages, you might want to try
516 <h3 class="SECT2"><a name="WINDOWOPEN" id="WINDOWOPEN">5.16. Why do I
517 keep seeing <span class="QUOTE">"PrivoxyWindowOpen()"</span> in raw
518 source code?</a></h3>
520 <p><span class="APPLICATION">Privoxy</span> is attempting to disable
521 malicious <a href="http://en.wikipedia.org/wiki/Javascript" target=
522 "_top">Javascript</a> in this case, with the <tt class=
523 "LITERAL">unsolicited-popups</tt> filter. <span class=
524 "APPLICATION">Privoxy</span> cannot tell very well <span class=
525 "QUOTE">"good"</span> code snippets from <span class=
526 "QUOTE">"bad"</span> code snippets.</p>
528 <p>If you see this in HTML source, and the page displays without
529 problems, then this is good, and likely some pop-up window was
530 disabled. If you see this where it is causing a problem, such as a
531 downloaded program source code file, then you should set an exception
532 for this site or page such that the integrity of the page stays in tact
533 by disabling all filtering.</p>
537 <h3 class="SECT2"><a name="DNSERRORS" id="DNSERRORS">5.17. I am getting
538 too many DNS errors like <span class="QUOTE">"404 No Such
539 Domain"</span>. Why can't Privoxy do this better?</a></h3>
541 <p>There are potentially several factors here. First of all, the DNS
542 resolution is done by the underlying operating system -- not
543 <span class="APPLICATION">Privoxy</span> itself. <span class=
544 "APPLICATION">Privoxy</span> merely initiates the process and hands it
545 off, and then later reports whatever the outcome was and tries to give
546 a coherent message if there seems to be a problem. In some cases, this
547 might otherwise be mitigated by the browser itself which might try some
548 work-arounds and alternate approaches (e.g adding <span class=
549 "QUOTE">"www."</span> to the URL).</p>
551 <p>In other cases, if <span class="APPLICATION">Privoxy</span> is being
552 chained with another proxy, this could complicate the issue, and cause
553 undue delays and timeouts. In the case of a <span class=
554 "QUOTE">"socks4a"</span> proxy, the socks server handles all the DNS.
555 <span class="APPLICATION">Privoxy</span> would just be the <span class=
556 "QUOTE">"messenger"</span> which is reporting whatever problem occurred
557 downstream, and not the root cause of the error.</p>
559 <p>In any case, versions newer than 3.0.3 include various improvements
560 to help <span class="APPLICATION">Privoxy</span> better handle these
565 <h3 class="SECT2"><a name="ALLCPU" id="ALLCPU">5.18. At one site
566 Privoxy just hangs, and starts taking all CPU. Why is this?</a></h3>
568 <p>This is probably a manifestation of the <span class="QUOTE">"100%
569 cpu"</span> problem that occurs on pages containing many (thousands
570 upon thousands) of blank lines. The blank lines are in the raw HTML
571 source of the page, and the browser just ignores them. But the pattern
572 matching in <span class="APPLICATION">Privoxy's</span> page filtering
573 mechanism is trying to match against absurdly long strings and this
574 becomes very CPU-intensive, taking a long, long time to complete.</p>
576 <p>Until a better solution comes along, disable filtering on these
577 pages, particularly the <tt class="LITERAL">js-annoyances</tt> and
578 <tt class="LITERAL">unsolicited-popups</tt> filters. If you run into
579 this problem with a recent <span class="APPLICATION">Privoxy</span>
580 version, please send a problem report.</p>
584 <h3 class="SECT2"><a name="SLOWCRAWL" id="SLOWCRAWL">5.19. I just
585 installed Privoxy, and all my browsing has slowed to a crawl. What
588 <p>This should not happen, and for the overwhelming number of users
589 world-wide, it does not happen. I would suspect some inadvertent
590 interaction of software components such as anti-virus software, spyware
591 protectors, personal firewalls or similar components. Try disabling (or
592 uninstalling) these one at a time and see if that helps. Either way, if
593 you are using a recent <span class="APPLICATION">Privoxy</span>
594 version, please report the problem.</p>
598 <h3 class="SECT2"><a name="PREVENTCOMP" id="PREVENTCOMP">5.20. Why do
599 my filters work on some sites but not on others?</a></h3>
601 <p>It's probably due to compression. It is a common practice for web
602 servers to send their content <span class="QUOTE">"compressed"</span>
603 in order to speed things up, and then let the browser <span class=
604 "QUOTE">"uncompress"</span> them. When compiled with zlib support
605 <span class="APPLICATION">Privoxy</span> can decompress content before
606 filtering, otherwise you may want to enable <a href=
607 "../user-manual/actions-file.html#PREVENT-COMPRESSION" target=
608 "_top">prevent-compression</a>.</p>
610 <p>As of <span class="APPLICATION">Privoxy</span> 3.0.9, zlib support
611 is enabled in the default builds.</p>
615 <h3 class="SECT2"><a name="SSL-WARNINGS" id="SSL-WARNINGS">5.21. On
616 some HTTPS sites my browser warns me about unauthenticated content, the
617 URL bar doesn't get highlighted and the lock symbol appears to be
618 broken. What's going on?</a></h3>
620 <p>Probably the browser is requesting ads through HTTPS and
621 <span class="APPLICATION">Privoxy</span> is blocking the requests.
622 Privoxy's error messages are delivered unencrypted and while it's
623 obvious for the browser that the HTTPS request is already blocked by
624 the proxy, some warn about unauthenticated content anyway.</p>
626 <p>To work around the problem you can redirect those requests to an
627 invalid local address instead of blocking them. While the redirects
628 aren't encrypted either, many browsers don't care. They simply follow
629 the redirect, fail to reach a server and display an error message
630 instead of the ad.</p>
632 <p>To do that, enable logging to figure out which requests get blocked
633 by <span class="APPLICATION">Privoxy</span> and add the hosts (no path
634 patterns) to a section like this:</p>
636 <table class="c2" border="0" width="100%">
640 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
647 <p>Additionally you have to configure your browser to contact
648 <span class="QUOTE">"127.0.0.1:0"</span> directly (instead of through
649 <span class="APPLICATION">Privoxy</span>).</p>
651 <p>To add a proxy exception in <span class="APPLICATION">Mozilla
652 Firefox</span> open the <span class="QUOTE">"Preferences"</span>, click
653 the <span class="QUOTE">"Settings"</span> button located on the
654 <span class="QUOTE">"Network"</span> tab in the <span class=
655 "QUOTE">"Advanced"</span> section, and add <span class=
656 "QUOTE">"127.0.0.1:0"</span> in the <span class="QUOTE">"No Proxy
657 for:"</span> field.</p>
661 <h3 class="SECT2"><a name="SE-LINUX" id="SE-LINUX">5.22. I get selinux
662 error messages. How can I fix this?</a></h3>
664 <p>Please report the problem to the creator of your selinux
667 <p>The problem is that some selinux policy writers aren't familiar with
668 the application they are trying to <span class="QUOTE">"secure"</span>
669 and thus create policies that make no sense.</p>
671 <p>In <span class="APPLICATION">Privoxy's</span> case the problem
672 usually is that the policy only allows outgoing connections for certain
673 destination ports (e.g. 80 and 443). While this may cover the standard
674 ports, websites occasionally use other ports as well. This isn't a
675 security problem and therefore <span class=
676 "APPLICATION">Privoxy's</span> default configuration doesn't block
679 <p>If you really want to block these ports (and don't be able to load
680 websites that don't use standard ports), you should configure Privoxy
681 to block these ports as well, so it doesn't trigger the selinux
686 <h3 class="SECT2"><a name="GENTOO-RICERS" id="GENTOO-RICERS">5.23. I
687 compiled <span class="APPLICATION">Privoxy</span> with Gentoo's portage
688 and it appears to be very slow. Why?</a></h3>
690 <p>Probably you unintentionally compiled <span class=
691 "APPLICATION">Privoxy</span> without threading support in which case
692 requests have to be serialized and only one can be served at the same
695 <p>Check your <span class="QUOTE">"USE"</span> flags and make sure they
696 include <span class="QUOTE">"threads"</span>. If they don't, add the
697 flag and rebuild <span class="APPLICATION">Privoxy</span>.</p>
699 <p>If you compiled <span class="APPLICATION">Privoxy</span> with
700 threading support (on POSIX-based systems), the <span class=
701 "QUOTE">"Conditional #defines"</span> section on <a href=
702 "http://config.privoxy.org/show-status" target=
703 "_top">http://config.privoxy.org/show-status</a> will list <span class=
704 "QUOTE">"FEATURE_PTHREAD"</span> as <span class=
705 "QUOTE">"enabled"</span>.</p>
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