1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01
2 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
8 <meta name="GENERATOR" content=
9 "Modular DocBook HTML Stylesheet Version 1.79">
10 <link rel="HOME" title="Privoxy Frequently Asked Questions" href=
12 <link rel="PREVIOUS" title="Miscellaneous" href="misc.html">
13 <link rel="NEXT" title=
14 "Contacting the developers, Bug Reporting and Feature Requests" href=
16 <link rel="STYLESHEET" type="text/css" href="../p_doc.css">
17 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
19 <body class="SECT1" bgcolor="#EEEEEE" text="#000000" link="#0000FF" vlink=
20 "#840084" alink="#0000FF">
21 <div class="NAVHEADER">
22 <table summary="Header navigation table" width="100%" border="0"
23 cellpadding="0" cellspacing="0">
25 <th colspan="3" align="center">
26 Privoxy Frequently Asked Questions
30 <td width="10%" align="left" valign="bottom">
31 <a href="misc.html" accesskey="P">Prev</a>
33 <td width="80%" align="center" valign="bottom">
35 <td width="10%" align="right" valign="bottom">
36 <a href="contact.html" accesskey="N">Next</a>
40 <hr align="LEFT" width="100%">
44 <a name="TROUBLE">5. Troubleshooting</a>
48 <a name="REFUSED">5.1. I cannot connect to any websites. Or, I am
49 getting <span class="QUOTE">"connection refused"</span> message
50 with every web page. Why?</a>
53 There are several possibilities:
58 <span class="APPLICATION">Privoxy</span> is not running.
59 Solution: verify that <span class="APPLICATION">Privoxy</span>
60 is installed correctly, has not crashed, and is indeed running.
61 Turn on <span class="APPLICATION">Privoxy's</span> logging, and
62 look at the logs to see what they say.
67 Or your browser is configured for a different port than what
68 <span class="APPLICATION">Privoxy</span> is using. Solution:
69 verify that <span class="APPLICATION">Privoxy</span> and your
70 browser are set to the same port (<tt class=
71 "LITERAL">listen-address</tt>).
76 Or if using a forwarding rule, you have a configuration problem
77 or a problem with a host in the forwarding chain. Solution:
78 temporarily alter your configuration and take the forwarders
84 Or you have a firewall that is interfering and blocking you.
85 Solution: try disabling or removing the firewall as a simple
93 <a name="ERROR503">5.2. Why am I getting a 503 Error
94 (WSAECONNREFUSED) on every page?</a>
97 More than likely this is a problem with your TCP/IP networking.
98 ZoneAlarm has been reported to cause this symptom -- even if not
99 running! The solution is to either fight the ZA configuration, or
100 uninstall ZoneAlarm, and then find something better behaved in its
101 place. Other personal firewall type products may cause similar type
102 problems if not configured correctly.
107 <a name="FLUSHIT">5.3. I just added a new rule, but the steenkin ad
108 is still getting through. How?</a>
111 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
113 be displayed without the need for any request to the server, and
114 <span class="APPLICATION">Privoxy</span> will not be involved.
115 Flush the browser's caches, and then try again.
118 If this doesn't help, you probably have an error in the rule you
119 applied. Try pasting the full URL of the offending ad into <a href=
120 "http://config.privoxy.org/show-url-info" target=
121 "_top">http://config.privoxy.org/show-url-info</a> and see if it
122 really matches your new rule. Blocking ads is like blocking spam: a
123 lot of tinkering is required to stay ahead of the game. And
124 remember you need to block the URL of the ad in question, which may
125 be entirely different from the site URL itself. Most ads are hosted
126 on different servers than the main site itself. If you right-click
127 on the ad, you should be able to get all the relevant information
128 you need. Alternately, you can find the correct URL by looking at
129 <span class="APPLICATION">Privoxy's</span> logs (you may need to
130 enable logging in the main config file if its disabled).
133 Below is a slightly modified real-life log snippet that originates
134 with one requested URL: <tt class="LITERAL">www.example.com</tt>
135 (name of site was changed for this example, the number of requests
136 is real). You can see in this the complexity of what goes into
137 making up this one <span class="QUOTE">"page"</span>. There are
138 eight different domains involved here, with thirty two separate
139 URLs requested in all, making up all manner of images, Shockwave
140 Flash, JavaScript, CSS stylesheets, scripts, and other related
141 content. Some of this content is obviously <span class=
142 "QUOTE">"good"</span> or <span class="QUOTE">"bad"</span>, but not
143 all. Many of the more questionable looking requests, are going to
144 outside domains that seem to be identifying themselves with
145 suspicious looking names, making our job a little easier. <span
146 class="APPLICATION">Privoxy</span> has <span class=
147 "QUOTE">"crunched"</span> (meaning caught and BLOCKED) quite a few
148 items in this example, but perhaps missed a few as well.
150 <table border="0" bgcolor="#E0E0E0" 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
193 Despite 12 out of 32 requests being blocked, the page looked, and
194 seemed to behave perfectly <span class="QUOTE">"normal"</span>
195 (minus some ads, of course).
200 <a name="BADSITE">5.4. One of my favorite sites does not work with
201 Privoxy. What can I do?</a>
204 First verify that it is indeed a <span class=
205 "APPLICATION">Privoxy</span> problem, by toggling off <span class=
206 "APPLICATION">Privoxy</span> through <a href=
207 "http://config.privoxy.org/toggle" target=
208 "_top">http://config.privoxy.org/toggle</a> (the toggle feature may
209 need to be enabled in the main <tt class="FILENAME">config</tt>),
210 and then shift-reloading the problem page (i.e. holding down the
211 shift key while clicking reload. Alternatively, flush your
212 browser's disk and memory caches).
215 If the problem went away, we know we have a configuration related
216 problem. Now go to <a href=
217 "http://config.privoxy.org/show-url-info" target=
218 "_top">http://config.privoxy.org/show-url-info</a> and paste the
219 full URL of the page in question into the prompt. See which actions
220 are being applied to the URL, and which matches in which actions
221 files are responsible for that. It might be helpful also to look at
222 your logs for this site too, to see what else might be happening
223 (note: logging may need to be enabled in the main config file).
224 Many sites are complex and require a number of related pages to
225 help present their content. Look at what else might be used by the
226 page in question, and what of that might be <span class=
227 "emphasis"><i class="EMPHASIS">required</i></span>. Now, armed with
228 this information, go to <a href=
229 "http://config.privoxy.org/show-status" target=
230 "_top">http://config.privoxy.org/show-status</a> and select the
231 appropriate actions files for editing.
234 You can now either look for a section which disables the actions
235 that you suspect to cause the problem and add a pattern for your
236 site there, or make up a completely new section for your site. In
237 any case, the recommended way is to disable only the prime suspect,
238 reload the problem page, and only if the problem persists, disable
239 more and more actions until you have identified the culprit. You
240 may or may not want to turn the other actions on again. Remember to
241 flush your browser's caches in between any such changes!
244 Alternately, if you are comfortable with a text editor, you can
245 accomplish the same thing by editing the appropriate actions file.
246 Probably the easiest way to deal with such problems when editing by
247 hand is to add your site to a <tt class="LITERAL">{ fragile }</tt>
248 section in <tt class="FILENAME">user.action</tt>, which is an alias
249 that turns off most <span class="QUOTE">"dangerous"</span> actions,
250 but is also likely to turn off more actions then needed, and thus
251 lower your privacy and protection more than necessary,
254 Troubleshooting actions is discussed in more detail in the <a href=
255 "../user-manual/appendix.html#ACTIONSANAT" target="_top">User
256 Manual appendix, Troubleshooting: the Anatomy of an Action</a>.
257 There is also an <a href=
258 "../user-manual/actions-file.html#ACT-EXAMPLES" target=
259 "_top">actions tutorial</a> with general configuration information
263 As a last resort, you can always see if your browser has a setting
264 that will bypass the proxy setting for selective sites. Modern
265 browsers can do this.
270 <a name="DUN">5.5. After installing Privoxy, I have to log in every
271 time I start IE. What gives?</a>
274 This is a quirk that affects the installation of <span class=
275 "APPLICATION">Privoxy</span>, in conjunction with Internet Explorer
276 and Internet Connection Sharing on Windows 2000 and Windows XP. The
277 symptoms may appear to be corrupted or invalid DUN settings, or
281 When setting up an NT based Windows system with <span class=
282 "APPLICATION">Privoxy</span> you may find that things do not seem
283 to be doing what you expect. When you set your system up you will
284 probably have set up Internet Connection Sharing (ICS) with Dial up
285 Networking (DUN) when logged in with administrator privileges. You
286 will probably have made this DUN connection available to other
287 accounts that you may have set-up on your system. E.g. Mum or Dad
288 sets up the system and makes accounts suitably configured for the
292 When setting up <span class="APPLICATION">Privoxy</span> in this
293 environment you will have to alter the proxy set-up of Internet
294 Explorer (IE) for the specific DUN connection on which you wish to
295 use <span class="APPLICATION">Privoxy</span>. When you do this the
296 ICS DUN set-up becomes user specific. In this instance you will see
297 no difference if you change the DUN connection under the account
298 used to set-up the connection. However when you do this from
299 another user you will notice that the DUN connection changes to
300 make available to "Me only". You will also find that you have to
301 store the password under each different user!
304 The reason for this is that each user's set-up for IE is user
305 specific. Each set-up DUN connection and each LAN connection in IE
306 store the settings for each user individually. As such this
307 enforces individual configurations rather than common ones. Hence
308 the first time you use a DUN connection after re-booting your
309 system it may not perform as you expect, and prompt you for the
310 password. Just set and save the password again and all should be
314 [Thanks to Ray Griffith for this submission.]
319 <a name="FTP">5.6. I cannot connect to any FTP sites. Privoxy is
323 <span class="APPLICATION">Privoxy</span> cannot act as a proxy for
324 FTP traffic, so do not configure your browser to use <span class=
325 "APPLICATION">Privoxy</span> as an FTP proxy. The same is true for
326 <span class="emphasis"><i class="EMPHASIS">any protocol other than
327 HTTP or HTTPS (SSL)</i></span>.
330 Most browsers understand FTP as well as HTTP. If you connect to a
331 site, with a URL like <tt class=
332 "LITERAL">ftp://ftp.example.com</tt>, your browser is making an FTP
333 connection, and not a HTTP connection. So while your browser may
334 speak FTP, <span class="APPLICATION">Privoxy</span> does not, and
335 cannot proxy such traffic.
338 To complicate matters, some systems may have a generic <span class=
339 "QUOTE">"proxy"</span> setting, which will enable various
340 protocols, including <span class="emphasis"><i class=
341 "EMPHASIS">both</i></span> HTTP and FTP proxying! So it is possible
342 to accidentally enable FTP proxying in these cases. And of course,
343 if this happens, <span class="APPLICATION">Privoxy</span> will
344 indeed cause problems since it does not know FTP. Newer version
345 will give a sane error message if a FTP connection is attempted.
346 Just disable the FTP setting and all will be well again.
349 Will <span class="APPLICATION">Privoxy</span> ever proxy FTP
350 traffic? Unlikely. There just is not much reason, and the work to
351 make this happen is more than it may seem.
356 <a name="MACOSXIE">5.7. In Mac OS X, I can't configure Microsoft
357 Internet Explorer to use Privoxy as the HTTP proxy.</a>
360 Microsoft Internet Explorer (in versions like 5.1) respects
361 system-wide network settings. In order to change the HTTP proxy,
362 open System Preferences, and click on the Network icon. In the
363 settings pane that comes up, click on the Proxies tab. Ensure the
364 "Web Proxy (HTTP)" checkbox is checked and enter <tt class=
365 "LITERAL">127.0.0.1</tt> in the entry field. Enter <tt class=
366 "LITERAL">8118</tt> in the Port field. The next time you start IE,
367 it should reflect these values.
372 <a name="MACOSXUNINSTALL">5.8. In Mac OS X, I dragged the Privoxy
373 folder to the trash in order to uninstall it. Now the finder tells
374 me I don't have sufficient privileges to empty the trash.</a>
377 Note: This ONLY applies to privoxy 3.0.6 and earlier.
380 Just dragging the <span class="APPLICATION">Privoxy</span> folder
381 to the trash is not enough to delete it. <span class=
382 "APPLICATION">Privoxy</span> supplies an <span class=
383 "APPLICATION">uninstall.command</span> file that takes care of
384 these details. Open the trash, drag the <span class=
385 "APPLICATION">uninstall.command</span> file out of the trash and
386 double-click on it. You will be prompted for confirmation and the
387 administration password.
390 The trash may still appear full after this command; emptying the
391 trash from the desktop should make it appear empty again.
396 <a name="MACOSXIMAGES">5.9. In Mac OS X Panther (10.3), images
397 often fail to load and/or I experience random delays in page
398 loading. I'm using <tt class="LITERAL">localhost</tt> as my
399 browser's proxy setting.</a>
402 We believe this is due to an IPv6-related bug in Mac OS X, but
403 don't fully understand the issue yet. In any case, changing the
404 proxy setting to <tt class="LITERAL">127.0.0.1</tt> instead of <tt
405 class="LITERAL">localhost</tt> works around the problem.
410 <a name="MACOSXACCOUNTDELETION">5.10. I just upgraded to Mac OS X
411 10.9 (Mavericks) and now <span class="APPLICATION">Privoxy</span>
412 has stopped working.</a>
415 The upgrade process to Mac OS X Mavericks (10.9) from an earlier
416 version of OS X deletes all user accounts that are either not part
417 of OS X itself or are not interactive user accounts (ones you log
418 in with). Since, for the sake of security, <span class=
419 "APPLICATION">Privoxy</span> runs as a non-privileged user that is
420 created by its installer (_privoxy), it can no longer start up once
421 that account gets deleted. The solution is to perform a complete
422 uninstall using the supplied <span class=
423 "APPLICATION">uninstall.command</span> script (either back up your
424 configuration files or select to not have the uninstaller remove
425 them when it prompts you) and then reinstall <span class=
426 "APPLICATION">Privoxy</span> using the installer package and merge
427 in your configuration.
432 <a name="NOHOSTNAME">5.11. My logs show many <span class=
433 "QUOTE">"Unable to get my own hostname"</span> lines. Why?</a>
436 <span class="APPLICATION">Privoxy</span> tries to get the hostname
437 of the system its running on from the IP address of the system
438 interface it is bound to (from the <tt class="FILENAME">config</tt>
439 file <span class="emphasis"><i class=
440 "EMPHASIS">listen-address</i></span> setting). If the system cannot
441 supply this information, <span class="APPLICATION">Privoxy</span>
445 Typically, this would be considered a minor system configuration
446 error. It is not a fatal error to <span class=
447 "APPLICATION">Privoxy</span> however, but may result in a much
448 slower response from <span class="APPLICATION">Privoxy</span> on
449 some platforms due to DNS timeouts.
452 This can be caused by a problem with the local <tt class=
453 "FILENAME">hosts</tt> file. If this file has been changed from the
454 original, try reverting it to see if that helps. Make sure whatever
455 name(s) are used for the local system, that they resolve both ways.
458 You should also be able to work around the problem with the <a
459 href="../user-manual/config.html#HOSTNAME" target="_top">hostname
465 <a name="INUSE">5.12. When I try to launch Privoxy, I get an error
466 message <span class="QUOTE">"port 8118 is already in use"</span>
467 (or similar wording). Why?</a>
470 Port 8118 is <span class="APPLICATION">Privoxy's</span> default TCP
471 <span class="QUOTE">"listening"</span> port. Typically this message
472 would mean that there is already one instance of <span class=
473 "APPLICATION">Privoxy</span> running, and your system is actually
474 trying to start a second <span class="APPLICATION">Privoxy</span>
475 on the same port, which will not work. (You can have multiple
476 instances but they must be assigned different ports.) How and why
477 this might happen varies from platform to platform, but you need to
478 check your installation and start-up procedures.
483 <a name="DEMORONIZER">5.13. Pages with UTF-8 fonts are garbled.</a>
486 This may be the result of an overly aggressive filter. The filters
487 that are enabled in the default configuration aren't expected to
488 cause problems like this. If you enabled the <span class=
489 "QUOTE">"demoronizer"</span> filter, please try temporarily
493 If that doesn't help, temporarily disable all filters to see if
494 another filter could be the culprit. If the problem disappears,
495 enable the filters one by one, until the problem reappears and the
496 offending filter is found.
499 Once the problem-causing filter is known, it can be fixed or
503 Upgrading <span class="APPLICATION">Privoxy</span>, or going to the
504 most recent <tt class="FILENAME">default.action</tt> file available
506 "https://sourceforge.net/project/showfiles.php?group_id=11118"
507 target="_top">SourceForge</a> might be worth a try, too.
512 <a name="DEMORONIZER2">5.14. Why are binary files (such as images)
513 corrupted when Privoxy is used?</a>
516 This may also be caused by an (<a href=
517 "trouble.html#DEMORONIZER">overly aggressive filter</a> in
518 conjunction with a web server that is misreporting the content
519 type. By default binary files are exempted from <span class=
520 "APPLICATION">Privoxy's</span> filtering (unless the web server by
521 mistake says the file is something else).
526 <a name="DEMORONIZER3">5.15. What is the <span class=
527 "QUOTE">"demoronizer"</span> and why is it there?</a>
530 The original demoronizer was a Perl script that cleaned up HTML
531 pages which were created with certain Microsoft products. MS has
532 used proprietary extensions to standardized font encodings (ISO
533 8859-1), which has caused problems for pages that are viewed with
534 non-Microsoft products (and are expecting to see a standard set of
535 fonts). The demoronizer corrected these errors so the pages
536 displayed correctly. <span class="APPLICATION">Privoxy</span>
537 borrowed from this script, introducing a filter based on the
538 original demoronizer, which in turn could correct these errors on
542 But this is only needed in some situations, and will cause serious
543 problems in some other situations.
546 If you are using Microsoft products, you do not need it. If you
547 need to view pages with UTF-8 characters (such as Cyrillic or
548 Chinese), then it will cause corruption of the fonts, and thus
549 <span class="emphasis"><i class="EMPHASIS">should not be
553 On the other hand, if you use non-Microsoft products, and you
554 occasionally notice weird characters on pages, you might want to
560 <a name="WINDOWOPEN">5.16. Why do I keep seeing <span class=
561 "QUOTE">"PrivoxyWindowOpen()"</span> in raw source code?</a>
564 <span class="APPLICATION">Privoxy</span> is attempting to disable
565 malicious <a href="http://en.wikipedia.org/wiki/Javascript" target=
566 "_top">Javascript</a> in this case, with the <tt class=
567 "LITERAL">unsolicited-popups</tt> filter. <span class=
568 "APPLICATION">Privoxy</span> cannot tell very well <span class=
569 "QUOTE">"good"</span> code snippets from <span class=
570 "QUOTE">"bad"</span> code snippets.
573 If you see this in HTML source, and the page displays without
574 problems, then this is good, and likely some pop-up window was
575 disabled. If you see this where it is causing a problem, such as a
576 downloaded program source code file, then you should set an
577 exception for this site or page such that the integrity of the page
578 stays in tact by disabling all filtering.
583 <a name="DNSERRORS">5.17. I am getting too many DNS errors like
584 <span class="QUOTE">"404 No Such Domain"</span>. Why can't Privoxy
588 There are potentially several factors here. First of all, the DNS
589 resolution is done by the underlying operating system -- not <span
590 class="APPLICATION">Privoxy</span> itself. <span class=
591 "APPLICATION">Privoxy</span> merely initiates the process and hands
592 it off, and then later reports whatever the outcome was and tries
593 to give a coherent message if there seems to be a problem. In some
594 cases, this might otherwise be mitigated by the browser itself
595 which might try some work-arounds and alternate approaches (e.g
596 adding <span class="QUOTE">"www."</span> to the URL).
599 In other cases, if <span class="APPLICATION">Privoxy</span> is
600 being chained with another proxy, this could complicate the issue,
601 and cause undue delays and timeouts. In the case of a <span class=
602 "QUOTE">"socks4a"</span> proxy, the socks server handles all the
603 DNS. <span class="APPLICATION">Privoxy</span> would just be the
604 <span class="QUOTE">"messenger"</span> which is reporting whatever
605 problem occurred downstream, and not the root cause of the error.
608 In any case, versions newer than 3.0.3 include various improvements
609 to help <span class="APPLICATION">Privoxy</span> better handle
615 <a name="ALLCPU">5.18. At one site Privoxy just hangs, and starts
616 taking all CPU. Why is this?</a>
619 This is probably a manifestation of the <span class="QUOTE">"100%
620 cpu"</span> problem that occurs on pages containing many (thousands
621 upon thousands) of blank lines. The blank lines are in the raw HTML
622 source of the page, and the browser just ignores them. But the
623 pattern matching in <span class="APPLICATION">Privoxy's</span> page
624 filtering mechanism is trying to match against absurdly long
625 strings and this becomes very CPU-intensive, taking a long, long
629 Until a better solution comes along, disable filtering on these
630 pages, particularly the <tt class="LITERAL">js-annoyances</tt> and
631 <tt class="LITERAL">unsolicited-popups</tt> filters. If you run
632 into this problem with a recent <span class=
633 "APPLICATION">Privoxy</span> version, please send a problem report.
638 <a name="SLOWCRAWL">5.19. I just installed Privoxy, and all my
639 browsing has slowed to a crawl. What gives?</a>
642 This should not happen, and for the overwhelming number of users
643 world-wide, it does not happen. I would suspect some inadvertent
644 interaction of software components such as anti-virus software,
645 spyware protectors, personal firewalls or similar components. Try
646 disabling (or uninstalling) these one at a time and see if that
647 helps. Either way, if you are using a recent <span class=
648 "APPLICATION">Privoxy</span> version, please report the problem.
653 <a name="PREVENTCOMP">5.20. Why do my filters work on some sites
654 but not on others?</a>
657 It's probably due to compression. It is a common practice for web
658 servers to send their content <span class=
659 "QUOTE">"compressed"</span> in order to speed things up, and then
660 let the browser <span class="QUOTE">"uncompress"</span> them. When
661 compiled with zlib support <span class="APPLICATION">Privoxy</span>
662 can decompress content before filtering, otherwise you may want to
664 "../user-manual/actions-file.html#PREVENT-COMPRESSION" target=
665 "_top">prevent-compression</a>.
668 As of <span class="APPLICATION">Privoxy</span> 3.0.9, zlib support
669 is enabled in the default builds.
674 <a name="SSL-WARNINGS">5.21. On some HTTPS sites my browser warns
675 me about unauthenticated content, the URL bar doesn't get
676 highlighted and the lock symbol appears to be broken. What's going
680 Probably the browser is requesting ads through HTTPS and <span
681 class="APPLICATION">Privoxy</span> is blocking the requests.
682 Privoxy's error messages are delivered unencrypted and while it's
683 obvious for the browser that the HTTPS request is already blocked
684 by the proxy, some warn about unauthenticated content anyway.
687 To work around the problem you can redirect those requests to an
688 invalid local address instead of blocking them. While the redirects
689 aren't encrypted either, many browsers don't care. They simply
690 follow the redirect, fail to reach a server and display an error
691 message instead of the ad.
694 To do that, enable logging to figure out which requests get blocked
695 by <span class="APPLICATION">Privoxy</span> and add the hosts (no
696 path patterns) to a section like this:
698 <table border="0" bgcolor="#E0E0E0" width="100%">
702 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
710 Additionally you have to configure your browser to contact <span
711 class="QUOTE">"127.0.0.1:0"</span> directly (instead of through
712 <span class="APPLICATION">Privoxy</span>).
715 To add a proxy exception in <span class="APPLICATION">Mozilla
716 Firefox</span> open the <span class="QUOTE">"Preferences"</span>,
717 click the <span class="QUOTE">"Settings"</span> button located on
718 the <span class="QUOTE">"Network"</span> tab in the <span class=
719 "QUOTE">"Advanced"</span> section, and add <span class=
720 "QUOTE">"127.0.0.1:0"</span> in the <span class="QUOTE">"No Proxy
726 <a name="SE-LINUX">5.22. I get selinux error messages. How can I
730 Please report the problem to the creator of your selinux policies.
733 The problem is that some selinux policy writers aren't familiar
734 with the application they are trying to <span class=
735 "QUOTE">"secure"</span> and thus create policies that make no
739 In <span class="APPLICATION">Privoxy's</span> case the problem
740 usually is that the policy only allows outgoing connections for
741 certain destination ports (e.g. 80 and 443). While this may cover
742 the standard ports, websites occasionally use other ports as well.
743 This isn't a security problem and therefore <span class=
744 "APPLICATION">Privoxy's</span> default configuration doesn't block
748 If you really want to block these ports (and don't be able to load
749 websites that don't use standard ports), you should configure
750 Privoxy to block these ports as well, so it doesn't trigger the
756 <a name="GENTOO-RICERS">5.23. I compiled <span class=
757 "APPLICATION">Privoxy</span> with Gentoo's portage and it appears
758 to be very slow. Why?</a>
761 Probably you unintentionally compiled <span class=
762 "APPLICATION">Privoxy</span> without threading support in which
763 case requests have to be serialized and only one can be served at
767 Check your <span class="QUOTE">"USE"</span> flags and make sure
768 they include <span class="QUOTE">"threads"</span>. If they don't,
769 add the flag and rebuild <span class="APPLICATION">Privoxy</span>.
772 If you compiled <span class="APPLICATION">Privoxy</span> with
773 threading support (on POSIX-based systems), the <span class=
774 "QUOTE">"Conditional #defines"</span> section on <a href=
775 "http://config.privoxy.org/show-status" target=
776 "_top">http://config.privoxy.org/show-status</a> will list <span
777 class="QUOTE">"FEATURE_PTHREAD"</span> as <span class=
778 "QUOTE">"enabled"</span>.
783 <a name="TAINTED-SOCKETS">5.24. What are tainted sockets and how do
787 <span class="APPLICATION">Privoxy</span> marks sockets as tainted
788 when it can't use them to serve additional requests. This does not
789 necessarily mean that something went wrong and information about
790 tainted sockets is only logged if connection debugging is enabled
794 For example server sockets that were used for CONNECT requests
795 (which are used to tunnel https:// requests) are considered tainted
796 once the client closed its connection to <span class=
797 "APPLICATION">Privoxy</span>. Technically <span class=
798 "APPLICATION">Privoxy</span> could keep the connection to the
799 server open, but the server would not accept requests that do not
800 belong to the previous TLS/SSL session (and the client may even
801 have terminated the session).
804 Server sockets are also marked tainted when a client requests a
805 resource, but closes the connection before <span class=
806 "APPLICATION">Privoxy</span> has completely received (and
807 forwarded) the resource to the client. In this case the server
808 would (probably) accept additional requests, but <span class=
809 "APPLICATION">Privoxy</span> could not get the response without
810 completely reading the leftovers from the previous response.
813 These are just two examples, there are currently a bit more than 25
814 scenarios in which a socket is considered tainted.
817 While sockets can also be marked tainted as a result of a technical
818 problem that may be worth fixing, the problem will be explicitly
824 <a name="PCRE-STACK-LIMIT">5.25. After adding my custom filters,
825 <span class="APPLICATION">Privoxy</span> crashes when visitting
829 This can happen if your custom filters require more memory than
830 <span class="APPLICATION">Privoxy</span> is allowed to use. Usually
831 the problem is that the operating system enforces a stack size
832 limit that isn't sufficient.
835 Unless the problem occurs with the filters available in the default
836 configuration, this is not considered a Privoxy bug.
839 To prevent the crashes you can rewrite your filter to use less
840 ressources, increase the relevant memory limit or recompile pcre to
841 use less stack space. For details please see the <a href=
842 "http://pcre.org/original/doc/html/pcrestack.html" target=
843 "_top">pcrestack man page</a> and the documentation of your
848 <div class="NAVFOOTER">
849 <hr align="LEFT" width="100%">
850 <table summary="Footer navigation table" width="100%" border="0"
851 cellpadding="0" cellspacing="0">
853 <td width="33%" align="left" valign="top">
854 <a href="misc.html" accesskey="P">Prev</a>
856 <td width="34%" align="center" valign="top">
857 <a href="index.html" accesskey="H">Home</a>
859 <td width="33%" align="right" valign="top">
860 <a href="contact.html" accesskey="N">Next</a>
864 <td width="33%" align="left" valign="top">
867 <td width="34%" align="center" valign="top">
870 <td width="33%" align="right" valign="top">
871 Contacting the developers, Bug Reporting and Feature Requests