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3 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
7 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
9 $Id: faq.sgml,v 1.28 2002/03/25 04:27:33 hal9 Exp $
11 Written by and Copyright (C) 2001 the SourceForge
12 PRIVOXY team. http://ijbswa.sourceforge.net
14 Based on the Internet Junkbuster originally written
15 by and Copyright (C) 1997 Anonymous Coders and
16 Junkbusters Corporation. http://www.junkbusters.com
21 <title>Privoxy Frequently Asked Questions</title>
23 <pubdate>$Id: faq.sgml,v 1.28 2002/03/25 04:27:33 hal9 Exp $</pubdate>
28 <orgname>By: Privoxy Developers</orgname>
35 The FAQ document gives users and developers alike answers to frequently asked
37 <application>Privoxy</application>. <application>Privoxy</application> is a web
38 proxy with advanced filtering capabilities for protecting privacy, filtering
39 web page content, managing cookies, controlling access, and removing ads,
40 banners, pop-ups and other obnoxious Internet
41 Junk. <application>Privoxy</application> has a very flexible configuration and
42 can be customized to suit individual needs and
43 tastes. <application>Privoxy</application> has application for both stand-alone
44 systems and multi-user networks.
47 You can find the latest version of the document at <ulink url="http://ijbswa.sourceforge.net/faq/">http://ijbswa.sourceforge.net/faq/</ulink>.
48 Please see the Contact section in the
49 <ulink url="http://ijbswa.sourceforge.net/user-manual/contact.html">user-manual</ulink> if you want to contact the developers.
53 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
59 <!-- ~~~~~ New section ~~~~~ -->
62 <sect1 id="introduction"><title>Introduction</title>
68 <!-- ~~~~~ New section ~~~~~ -->
70 <sect1 id="questions"><title>Frequently Asked Questions</title>
72 <!-- ~~~~~ New section ~~~~~ -->
74 <sect2 id="general"><title>General Information</title>
76 <sect3 id="newjb"><title>What is this new version of <application>Privoxy</application>?</title>
78 The original <application>Internet Junkbuster</application> (tm) is a
79 copyrighted product of <ulink url="http://www.junkbusters.com">Junkbusters
80 Corporation</ulink>. Development of this effort stopped some time ago as of
81 version 2.0.2. Stefan Waldherr started the ijbswa project on <ulink
82 url="http://ijbswa.sourceforge.net">Sourceforge</ulink> to rekindle
83 development. Other developers subsequently joined with Stefan, and have
84 since added many new features, refinements and enhancements.
87 The new <application>Privoxy</application> started with the same
88 code base, but has changed significantly at this point.
95 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why a name change at all?</title>
97 <application>Privoxy</application> is for <quote>Privacy Enhancing Proxy</quote>.
98 There are possible legal complications from the continued use of the
99 <application>Junkbuster</application> name, which is a trademark of
100 <ulink url="http://junkbusters.com">The Junkbusters Corporation</ulink>.
101 There are no objections from Junkbusters Corporation to the project
106 The developers also believed that there so many changes from the original
107 code, that it was time to make a clean break from the past and make
108 a name in their own right.
113 <sect3 id="differs"><title>How does it differ from the old <application>Junkbuster?</application></title>
115 All the old features remain. The new <application>Privoxy</application>
116 still blocks ads and banners, still manages cookies, and still helps protect
117 your privacy. But, these are all enhanced, and many new features have been
118 added, all in the same vein.
121 The configuration has changed significantly as well. This is something that
122 users will notice right off the bat. The <quote>blocklist</quote> file does
123 not exist any more. This is replaced by <quote>actions</quote> files, such
124 as <filename>default.actions</filename>. This is where most of the per site
125 configuration is now.
130 <sect3 id="features"><title>What are some of the new features?</title>
132 This section is in both user-manual and faq. Please keep in sync!!!
139 Integrated browser based configuration and control utility (<ulink
140 url="http://p.p">http://p.p</ulink>). Browser-based tracing of rule
147 Modularized configuration that will allow for system wide settings, and
148 individual user settings. (not implemented yet, probably a 3.1 feature)
154 Blocking of annoying pop-up browser windows.
160 HTTP/1.1 compliant (most, but not all 1.1 features are supported).
166 Support for Perl Compatible Regular Expressions in the configuration files, and
167 generally a more sophisticated and flexible configuration syntax over
180 Web page content filtering (removes banners based on size,
181 invisible <quote>web-bugs</quote>, JavaScript, pop-ups, status bar abuse,
188 Bypass many click-tracking scripts (avoids script redirection).
195 Multi-threaded (POSIX and native threads).
201 Auto-detection and re-reading of config file changes.
207 User-customizable HTML templates (e.g. 404 error page).
213 Improved cookie management features (e.g. session based cookies).
219 Builds from source on most UNIX-like systems. Packages available for: Linux
220 (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11 and AmigaOS.
227 In addition, the configuration is much more powerful and versatile over-all.
236 <sect3 id="proxymoron"><title>What is a <quote>proxy</quote>? How does
237 <application>Privoxy</application> work? </title>
239 When you connect to a web site with <application>Privoxy</application>,
240 you are really connecting to your locally running version of
241 <application>Privoxy</application>. <application>Privoxy</application>
242 intercepts your requests for the web page, and relays that to the
243 <quote>real</quote> web site. The web site sends the HTTP data stream
244 back to <application>Privoxy</application>, where
245 <application>Privoxy</application> can work its magic before it
246 relays this data back to your web browser.
250 Since <application>Privoxy</application> sits between you and the
251 WWW, it is in a position to intercept and completely manage all web traffic and
252 HTTP content before it gets to your browser.
253 <application>Privoxy</application> uses various programming methods to do
254 this, all of which is under your control via the various configuration
259 There are many kinds of proxies. <application>Privoxy</application> best
260 fits the <quote>filtering proxy</quote> category.
265 <sect3 id="browsers2"><title>My browser does the same things as
266 <application>Privoxy</application>. Why should I use
267 <application>Privoxy</application> at all?</title>
269 Modern browsers do indeed have <emphasis>some</emphasis> of the same
270 functionality as <application>Privoxy</application>. Maybe this is
271 adequate for you. But <application>Privoxy</application> is much more
272 versatile and powerful, and can do a number of things that browsers just can't.
275 In addition, a proxy is good choice if you use multiple browsers, or
276 have a LAN with multiple computers. This way all the configuration
277 is in one place, and you don't have to maintain a similar configuration
278 for possibly many browsers.
285 <sect3 id="license"><title>Is there is a license or fee? What about a
286 warranty? Registration?</title>
288 <application>Privoxy</application> is licensed under the
289 GNU General Public License (GPL). It is free to use, copy,
290 modify or distribute as you wish under the terms of this license.
292 url="http://www.gnu.org/copyleft/gpl.html">http://www.gnu.org/copyleft/gpl.html</ulink>
296 There is no warranty of any kind, expressed, implied or otherwise. That is
297 something that would cost real money ;-) There is no registration either.
298 <application>Privoxy</application> really is <emphasis>free</emphasis>
304 <sect3 id="jointeam"><title>I would like to help you, what do I do?</title>
306 <sect4 id="jointeam-money"><title>Money Money Money</title>
308 We, of course, welcome donations and use the money for domain registering,
309 regular world-wide get-togethers (hahaha). Anyway, we'll soon describe the
310 process how to donate money to the team.
314 <sect4 id="jointeam-work"><title>You want to work with us?</title>
316 Well, helping the team is always a good idea. We welcome new developers,
317 RPM gurus or documentation makers. Simply get an account on sourceforge.net
318 and mail your id to the developer mailing list. Then read the
319 section Quickstart in the developers manual.
322 Once we have added you to the team, you'll have write access to the CVS
323 repository, and together we'll find a suitable task for you.
332 <!-- ~~~~~ New section ~~~~~ -->
334 <sect2 id="installation"><title>Installation</title>
336 <sect3 id="newinstall"><title>Can I install the new
337 <application>Privoxy</application> over the old one?</title>
339 We recommend you uninstall the old <application>Junkbuster</application>
340 first to minimize conflicts and confusion. You may want to
341 save your old configuration files for future reference. The configuration
342 is substantially changed.
346 url="http://ijbswa.sourceforge.net/user-manual/">user-manual</ulink> for
347 platform specific installation instructions. [FIXME: This is meant for after
348 the name change for 3.0!]
354 <title id="firststep">I just installed <application>Privoxy</application>. Is there anything
355 special I have to do now?</title>
358 All browsers must be told to use <application>Privoxy</application>
359 as a proxy by specifying the correct proxy address and port number
360 in the appropriate configuration area for the browser. See below.
367 <sect3 id="localhost"><title>What is the proxy address of <application>Privoxy</application>?</title>
369 If you set up the <application>Privoxy</application> to run on
370 the computer you browse from (rather than your ISP's server or some
371 networked computer on a LAN), the proxy will be on <quote>localhost</quote>
372 (which is the special name used by every computer on the Internet to refer
373 to itself) and the port will be 8118 (unless you have <application>Privoxy</application> to run on a different port with the
374 <emphasis>listen-address</emphasis> config option).
377 When configuring your browser's proxy settings you typically enter
378 the word <quote>localhost</quote> in the boxes next to <quote>HTTP</quote>
379 and <quote>Secure</quote> (HTTPS) and then the number <quote>8118</quote>
380 for <quote>port</quote>. This tells your browser to send all web
381 requests to <application>Privoxy</application> instead of directly to the
385 <application>Privoxy</application> can also be used to proxy for
386 a Local Area Network. In this case, your would enter either the IP
387 address of the LAN host where <application>Privoxy</application>
388 is running, or the equivalent hostname. Port assignment would be
392 <application>Privoxy</application> does not currently handle
393 protocols such as FTP, SMTP, IM, IRC, ICQ, or other Internet
399 <title id="nothing">I just installed <application>Privoxy</application>, and nothing is happening.
400 All the ads are there. What's wrong?</title>
403 Did you configure your browser to use <application>Privoxy</application>
404 as a proxy? It does not sound like it. See above. You might also try flushing
405 the browser's caches to force a full re-reading of pages. You can verify
406 that <application>Privoxy</application> is running, and your browser
407 is correctly configured by entering the special URL:
408 <ulink url="http://p.p/">http://p.p/</ulink>. This should give you
409 a banner that says <quote>This is Privoxy</quote> and
410 access to <application>Privoxy's</application> internal configuration.
411 If you see this, then you are good to go. If not, the browser or
412 <application>Privoxy</application> are not set up correctly.
421 <!-- ~~~~~ New section ~~~~~ -->
423 <sect2 id="configuration"><title>Configuration</title>
425 <sect3 id="newconfig"><title>Can I use my old config files?</title>
427 There are major changes to <application>Junkbuster</application>
428 configuration from version 2.0.x to 2.9.x and later. The older files will
429 not work at all. If this is the case, you will need to re-enter your old
430 data into the new configuration structure. This is probably also a good
431 recommendation even if upgrading from 2.9.x to 3.x since there were
432 many minor changes along the way.
437 <title id="actionsfile">What is an <quote>actions</quote> file?</title>
440 <quote>actions</quote> files are where various actions that
441 <application>Privoxy</application> might take, are configured.
442 Typically, you would define a set of default actions that apply
443 to all URLs, then add exceptions to these defaults.
447 Actions can be defined on a per site basis, or for groups of sites. Actions
448 can also be grouped together and then applied to one or more sites. There
449 are many possible actions that might apply to any given site. As an example,
450 if we are blocking cookies as one of our default
451 <application>actions</application>, but need to accept cookies from a given
452 site, we would define this in our <quote>actions</quote> file.
457 <application>Privoxy</application> comes with several default
458 <application>actions</application> files, with varying degrees
459 of filtering and blocking, as starting points for your own
460 configuration (see below).
465 <sect3 id="actionss">
466 <title>The <quote>actions</quote>concept confuses me. Please list
467 some of these <quote>actions</quote>.</title>
469 These are all explained in the
470 <ulink url="http://ijbswa.sourceforge.net/user-manual/configuration.html#ACTIONSFILE">user-manual</ulink>.
471 Please refer to that.
477 <title id="actconfig">How are actions files configured? What is the easiest
478 way to do this?</title>
481 The easiest way to do this, is to access <application>Privoxy</application>
482 with your web browser at <ulink url="http://p.p/">http://p.p/</ulink>,
484 "<ulink url="http://ijbswa.sourceforge.net/config/edit-actions">Edit the actions list</ulink>"
485 from the selection list. You can also do this by editing the appropriate
486 file with a text editor.
492 url="http://ijbswa.sourceforge.net/user-manual/configuration.html#ACTIONSFILE">user-manual</ulink> for a
493 detailed explanation of these and other configuration files, and their
494 various options and syntax.
500 FIXME: Commenting these out until we have some data there. HB 03/17/02.
502 <sect3 id="yahoo"><title>How can I make my Yahoo account work?</title>
508 <sect3 id="hotmail"> <title>How can I make my Hotmail account work?</title>
514 <sect3 id="gmx"> <title>How can I make my GMX account work?</title>
521 <sect3 id="configfiles"> <title>What are the differences between
522 intermediate.action, basic.action, etc.?</title>
524 Configuring <application>Privoxy</application> is not easy. To help you get
525 started, we provide you with three different default configurations. The
526 following table shows you, which features are enabled in each configuration.
529 <table frame=all><title>Default Configurations</title>
530 <tgroup cols=5 align=left colsep=1 rowsep=1>
538 <entry>Feature</entry>
539 <entry>default.action</entry>
540 <entry>basic.action</entry>
541 <entry>intermediate.action</entry>
542 <entry>advanced.action</entry>
548 <!-- <entry>f1</entry> -->
549 <!-- <entry>f2</entry> -->
550 <!-- <entry>f3</entry> -->
551 <!-- <entry>f4</entry> -->
552 <!-- <entry>f5</entry> -->
559 <entry>ad-filtering</entry>
567 <entry>blank image</entry>
575 <entry>de-animate GIFs</entry>
583 <entry>referer forging</entry>
591 <entry>jon's +no-cookies-keep (i.e. session cookies only)</entry>
599 <entry>no-popup windows</entry>
607 <entry>fast redirects</entry>
615 <entry>hide-referrer</entry>
623 <entry>hide-useragent</entry>
631 <entry>content-modification</entry>
639 <entry>feature-x</entry>
647 <entry>feature-y</entry>
655 <entry>feature-z</entry>
668 <sect3 id="browseconfig"> <title>Why can I change the configuration with a
669 browser? Does that not raise security issues?</title>
671 What I don't understand, is how I can browser edit the config file as a
672 regular user, while the whole /etc/privoxy hierarchy belongs to the user
673 "privoxy", with only 644 perms.
676 When you use the browser-based editor, <application>Privoxy</application>
677 itself is writing to the config files. Because
678 <application>Privoxy</application> is running as the user "privoxy", it can
679 update the config files.
682 If you don't like this, setting "enable-edit-actions 0" in the config file
683 will disable the browser-based editor. If you're that paranoid, you should
684 also consider setting "enable-remote-toggle 0" to prevent browser-based
685 enabling/disabling of <application>Privoxy</application>.
688 Note that normally only local users can connect to <application>Privoxy</application>, so this is not
689 (normally) a security problem.
695 <title id="filterfile">What is a <quote>default.filter</quote>?</title>
697 The <quote>default.filter</quote> file is used to <quote>filter</quote> any
698 page content. By <quote>filtering</quote> we mean it can modify, remove,
699 or change <emphasis>anything</emphasis> on the page, including HTML tags, and
700 JavaScript. Regular expressions are used to accomplish this. This is
701 potentially a very powerful feature, but requires some expertise.
705 If you are familiar with regular expressions, and HTML, you can look at
706 the provided <filename>default.filter</filename> with a text editor and see
707 some of things it can be used for.
711 Presently, there is no GUI editor option for this part of the configuration,
712 but you can disable/enable various sections of the included default
713 file with the Actions List Editor from your browser.
719 <title id="lanconfig">How can I set up <application>Privoxy</application> to act as a proxy for my
722 By default, <application>Privoxy</application> only responds to requests
723 from localhost. To have it act as a server for a network, this needs to be
724 changed in the main config file where the <application>Privoxy</application>
725 configuration is located. In that file is a <quote>listen-address</quote>
726 option. It may be commented out with a <quote>#</quote> symbol. Make sure
727 it is uncommented, and assign it the address of the LAN gateway interface,
728 and port number to use:
733 listen-address 192.168.1.1:8118
738 Save the file, and restart <application>Privoxy</application>. Configure
739 all browsers on the network then to use this address and port number.
746 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
748 This is a configuration option for images that
749 <application>Privoxy</application> is stopping. You have the choice <!-- of
750 the --> <!-- <application>Privoxy</application> logo, --> a checkerboard
751 pattern (this scales better), a transparent 1x1 GIF image, or a custom URL or
756 If you want to see nothing, then change the <quote>+image-blocker</quote>
757 action to <quote>+image-blocker{blank}</quote>. This can be done from the
758 <quote>Edit Actions List</quote> selection at <ulink
759 url="http://p.p/">http://p.p/</ulink>. Or by hand editing the appropriate
760 actions file. This will only effect what is defined as <quote>images</quote>
769 <title id="whyseeum">Why would anybody want to see the checkerboard?</title>
771 This can be helpful for troubleshooting problems. It might also be good
772 for anyone new to <application>Privoxy</application> so that they can
773 see if their favorite pages are displaying correctly, and
774 <application>Privoxy</application> is not inadvertently removing something
781 <title id="blockedisugly">I see large red banners on some pages that say
782 <quote>Blocked</quote>. How do I get rid of this?</title>
784 These are URLs that match something in one of
785 <application>Privoxy's</application> block actions (+block). It is meant
786 to be a warning so that you know something has been blocked and an easy way
787 for you to see why. These are handled differently than what has been defined
788 as <quote>images</quote> (e.g. ad banners). If you want them to be treated
789 as if they were images, so that they can be invisible, then move the
790 offending URL from the <quote>+block</quote> section to the
791 <quote>+imageblock</quote> section of your actions file. Alternately, you
792 could modify the <quote><filename>block</filename></quote> HTML template that
793 is used by <application>Privoxy</application> to display this, and make it
794 something more to your liking.
801 <!-- ~~~~~ New section ~~~~~ -->
803 <sect2 id="misc"><title>Misc</title>
806 <title id="slowsme">How much does <application>Privoxy</application> slow my browsing down? This
807 has to add extra time to browsing.</title>
809 It should not slow you down any in real terms, and may actually help
810 speed things up since ads, banners and other junk are not being displayed.
811 The actual processing time required by <application>Privoxy</application>
812 itself for each page, is relatively small in the overall scheme of things,
813 and happens very quickly. This is typically more than offset by time saved
814 not downloading and rendering ad images.
818 <quote>Filtering</quote> via the <filename>filterfile</filename>
819 mechanism may cause a perceived slowdown, since the entire page is buffered
820 before displaying. See below.
827 <sect3 id="loadingtimes"><title>I noticed considerable
828 delays in page requests compared to the old Junkbuster. What's wrong?</title>
830 Using the default filtering configuration, I noticed considerable delays in
831 page requests compared to the old Junkbuster. Loading pages with large contents
832 seemed to take forever, then suddenly delivering all the content at once.
835 The whole content must be loaded in order to filter, and nothing is is
836 sent to the browser during this time. The loading time does not really
837 change in real numbers, but the feeling is different, because most
838 browsers are able to start rendering incomplete content, giving the
839 user a feeling of "it works".
842 To modify the content of a page (i.e. make frames resizeable again, etc.) and
843 not just replace ads, <application>Privoxy</application> needs to download the
844 entire page first, do its content magic and then send the page to the browser.
849 <sect3 id="configurl"><title>What is the "http://p.p/"?</title>
851 Since <application>Privoxy</application> sits between your web browser and the Internet, it can be
852 programmed to handle certain pages specially.
856 With recent versions of <application>Privoxy</application> (version 2.9.x), you can get some
857 information about <application>Privoxy</application> and change some settings by going to
858 http://p.p/ or, equivalently, http://ijbswa.sourceforge.net/config/
859 (Note that p.p is far easier to type but may not work in some
864 These pages are *not* forwarded to a server on the Internet - instead they are
865 handled by a special web server which is built in to <application>Privoxy</application>.
869 If you are not running <application>Privoxy</application>, then http://p.p/ will fail, and
870 http://ijbswa.sourceforge.net/config/ will return a web page telling you
871 you're not running <application>Privoxy</application>.
875 If you have version 2.0.2, then the equivalent is
876 http://example.com/show-proxy-args (but you get far less information, and you
877 should really consider upgrading to 2.9.x).
882 FIXME: commented out until we have data. HB 03/18/02.
884 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
890 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
891 (e.g. squid)?</title>
898 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
900 No. The format of the blocklists has changed significantly in the versions
901 2.9.x. Once we have released the new version, there will again be
902 blocklists that you can update automatically.
906 <sect3 id="newads"><title>How can I submit new ads?</title>
908 As of now, please discontinue to submit new ad blocking infos. Once we
909 have released the new version, there will again be a form on the website,
910 which you can use to contribute new ads.
914 <sect3 id="ip"><title>How can I hide my IP address?</title>
916 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
917 the server needs to know your IP address to send the answer to you.
920 Fortunately there are many publicly usable anonymous proxies out there, which
921 solve the problem by providing a further level of indirection between you and
922 the web server, shared by many people and thus letting your requests "drown"
923 in white noise of unrelated requests as far as user tracking is concerned.
926 Most of them will, however, log your IP address and make it available to the
927 authorities in case you abuse that anonymity for criminal purposes. In fact
928 you can't even rule out that some of them only exist to *collect* information
929 on (those suspicious) people with a more than average preference for privacy.
932 You can find a list of anonymous public proxies at <ulink
933 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
938 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
940 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
941 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
942 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
947 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
949 No. Your chances of remaining anonymous are greatly improved, but unless you
950 are an expert on Internet security it would be safest to assume that
951 everything you do on the Web can be traced back to you.
954 <application>Privoxy</application> can remove various information about you,
955 and allows <emphasis>you</emphasis> more freedom to decide which sites
956 you can trust. But it's still possible that web sites can find out who you
957 are. Here's one way this can happen.
960 A few browsers disclose the user's email address in certain situations, such
961 as when transferring a file by FTP. <application>Privoxy</application>
962 does not filter FTP. If you need this feature, or are concerned about the
963 mail handler of your browser disclosing your email address, you might
964 consider products such as <application>NSClean</application>.
967 Browsers available only as binaries could use non-standard headers to give
968 out any information they can have access to: see the manufacturer's license
969 agreement. It's impossible to anticipate and prevent every breach of privacy
970 that might occur. The professionally paranoid prefer browsers available as
971 source code, because anticipating their behavior is easier. Trust the source,
978 <title id="sitebreak">Might some things break because header information is
979 being altered?</title>
982 Definitely. More and more sites use HTTP header content to decide what to
983 display and how to display it. There is many ways that this can be handled,
984 so having hard and fast rules, is tricky.
988 <quote>USER AGENT</quote> in particular is often used in this way to identify
989 the browser, and adjust content accordingly. Changing this now is not
990 recommended, since so many sites do look for this. You may get undesirable
991 results by changing this.
995 For instance, different browsers use different encodings of Russian and Czech
996 characters, certain web servers convert pages on-the-fly according to the
997 User Agent header. Giving a <quote>User Agent</quote> with the wrong
998 operating system or browser manufacturer causes some sites in these languages
999 to be garbled; Surfers to Eastern European sites should change it to
1000 something closer. And then some page access counters work by looking at the
1001 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1002 weather maps of Intellicast have been blocked by their server when no
1003 <quote>REFERER</quote> or cookie is provided, is another example. There are
1004 many, many other ways things can go wrong when trying to fool a web server.
1008 If you have problems with a site, you will have to adjust your configuration
1009 accordingly. Cookies are probably the most likely adjustment that may
1010 be required, but by no means the only one.
1018 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1019 speed up web browsing?</title>
1021 No, it does not have this ability at all. You want something like
1022 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1023 before you ask, <application>Privoxy</application> can co-exist
1024 with other kinds of proxies like <quote>Squid</quote>.
1029 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1031 Not in the way you mean, or in the way a true firewall can, or a proxy that
1032 has this specific capability. <application>Privoxy</application> can help
1033 protect your privacy, but not really protect you from intrusion attempts.
1039 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1040 and ugly looking. Can't a better font be used?</title>
1043 This is not a font problem. The logo is an image that is created by
1044 <application>Privoxy</application> on the fly. So as to not waste
1045 memory, the image is rather small. The blockiness comes when the
1046 image is scaled to fill a largish area. There is not much to be done
1047 about this, other than to use one of the other
1048 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1049 <emphasis>blank</emphasis>, or a URL of your choosing.
1052 Given the above problem, we have decided to remove the logo option entirely.
1058 <title id="wasted">I have large empty spaces now where ads used to be.
1059 Why does <application>Privoxy</application> leave these large gaps?</title>
1061 It would be easy enough to just eliminate this space altogether, rather than
1062 fill it with blank space. But, this would create problems with many pages
1063 that use the overall size of the ad to help organize the page layout and
1064 position the various components of the page where they were intended to be.
1065 It is best left this way.
1071 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1073 This is a limitation since HTTPS transactions are encrypted SSL sessions
1074 between your browser and the secure site, and are meant to be reliably
1075 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1076 header information are also encrypted from the time they leave your browser,
1077 to the site, and vice versa. <application>Privoxy</application> does not
1078 try to unencrypt this information, so it just passes through as is.
1079 <application>Privoxy</application> can still catch images and ads that
1080 are embedded in the SSL stream though.
1087 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1088 secure is it? Do I need to take any special precautions?</title>
1090 There are no known exploits that might effect
1091 <application>Privoxy</application>. On Unix-like systems,
1092 <application>Privoxy</application> can run as a non-privileged
1093 user, which is how we recommend it be run. Also, by default
1094 <application>Privoxy</application> only listens to requests
1095 from <quote>localhost</quote>. It is not itself directly exposed to the
1096 Internet in this configuration. If you want to have
1097 <application>Privoxy</application> serve as a LAN proxy, this will have to
1098 be opened up to allow for LAN requests. In this case, we'd recommend
1099 you specify only the LAN gateway address, e.g. 192.168.1.1 in the main
1100 <application>Privoxy</application> config file. All LAN hosts can then use
1101 this as their proxy address in the browser proxy configuration. In this way,
1102 <application>Privoxy</application> will not listen on any external ports.
1103 Of course, a firewall is always good too. Better safe than sorry.
1111 <!-- ~~~~~ New section ~~~~~ -->
1114 <title id="trouble">Troubleshooting</title>
1117 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1118 with every web page?</title>
1120 Either <application>Privoxy</application> is not running, or your
1121 browser is configured for a different port than what
1122 <application>Privoxy</application> is using.
1126 The old <application>Privoxy</application> (and also
1127 <application>Junkbuster</application>) used port 8000 by
1128 default. This has been changed to port 8118 now, due to a conflict
1129 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1130 you need to change your browser to the new port number, or alternately
1131 change <application>Privoxy's</application> <quote>listen-address</quote>
1132 setting in the <filename>config</filename> file used to start
1133 <application>Privoxy</application>.
1139 <title id="flushit">I just added a new rule, but the steenkin ad is
1140 still getting through. How?</title>
1142 If the ad had been displayed before you added its URL, it will probably be
1143 held in the browser's cache for some time, so it will be displayed without
1144 the need for any request to the server, and <application>Privoxy</application>
1145 will not be in the picture. The best thing to do is try flushing the browser's
1146 caches. And then try again.
1150 If this doesn't help, you probably have an error in the rule you
1151 applied. Try pasting the full URL of the offending ad into <ulink
1152 url="http://ijbswa.sourceforge.net/config/show-url-info">http://ijbswa.sourceforge.net/config/show-url-info</ulink>
1153 and see if any actions match your new rule.
1159 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1160 What can I do?</title>
1163 First verify that it is indeed a <application>Privoxy</application> problem,
1164 by disabling <application>Privoxy</application> filtering and blocking.
1165 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1166 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1171 If still a problem, go to <quote>Show which actions apply to a URL and
1172 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1173 the full URL of the page in question into the prompt. See which actions are
1174 being applied to the URL. Now, armed with this information, go to <quote>Edit
1175 the actions list</quote>. Here you should see various sections that have
1176 various <application>Privoxy</application> features disabled for specific
1177 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1178 sign) in front of them. Add your problem page URL to one of these sections
1179 that looks like it is disabling the feature that is causing the
1180 problem. Re-try the page. There might be some trial and error involved. This
1181 is discussed in a little more detail in the <ulink
1182 url="http://ijbswa.sourceforge.net/user-manual/appendix.html#ACTIONSANAT">user-manual
1188 Alternately, if you are comfortable with a text editor, you can accomplish
1189 the same thing by editing the appropriate <quote>actions</quote> file.
1195 <title id="time">What time is it?</title>
1206 <!-- ~~~~~ New section ~~~~~ -->
1208 FIXME: Commented out until we have something to put here. HB 03/18/02.
1209 <sect1 id="knownissues"><title>Known Issues</title>
1215 <!-- ~~~~~ New section ~~~~~ -->
1216 <sect1 id="contact"><title>Contact the developers</title>
1217 <para>Please see the user manual for information on how to contact the developers.
1221 <!-- ~~~~~ New section ~~~~~ -->
1222 <sect1 id="copyright"><title>Copyright and History</title>
1223 <para>Please see the user manual for information on Copyright and History.
1227 <!-- ~~~~~ New section ~~~~~ -->
1228 <sect1 id="seealso"><title>See also</title>
1229 <para>Please see the user manual for information on references.
1235 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1237 Last modified: Mon Sep 10 19:22:09 CEST 2001
1239 This program is free software; you can redistribute it
1240 and/or modify it under the terms of the GNU General
1241 Public License as published by the Free Software
1242 Foundation; either version 2 of the License, or (at
1243 your option) any later version.
1245 This program is distributed in the hope that it will
1246 be useful, but WITHOUT ANY WARRANTY; without even the
1247 implied warranty of MERCHANTABILITY or FITNESS FOR A
1248 PARTICULAR PURPOSE. See the GNU General Public
1249 License for more details.
1251 The GNU General Public License should be included with
1252 this file. If not, you can view it at
1253 http://www.gnu.org/copyleft/gpl.html
1254 or write to the Free Software Foundation, Inc., 59
1255 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1258 Revision 1.28 2002/03/25 04:27:33 hal9
1259 New section related to name change.
1261 Revision 1.25 2002/03/24 16:08:08 swa
1262 we are too lazy to make a block-built
1263 privoxy logo. hence removed the option.
1265 Revision 1.24 2002/03/24 15:46:20 swa
1266 name change related issue.
1268 Revision 1.23 2002/03/24 12:33:01 swa
1271 Revision 1.22 2002/03/24 11:51:00 swa
1272 name change. changed filenames.
1274 Revision 1.21 2002/03/24 11:01:06 swa
1277 Revision 1.20 2002/03/23 15:13:11 swa
1278 renamed every reference to the old name with foobar.
1279 fixed "application foobar application" tag, fixed
1280 "the foobar" with "foobar". left junkbustser in cvs
1281 comments and remarks to history untouched.
1283 Revision 1.19 2002/03/21 17:01:54 hal9
1286 Revision 1.18 2002/03/18 16:40:31 hal9
1289 Revision 1.17 2002/03/18 03:53:53 hal9
1292 Revision 1.16 2002/03/17 21:32:56 hal9
1293 A few more additions.
1295 Revision 1.15 2002/03/17 07:25:59 hal9
1296 Correcting some of my typos, and some additions.
1298 Revision 1.14 2002/03/17 02:39:13 hal9
1299 A little more added ...
1301 Revision 1.13 2002/03/17 00:22:20 hal9
1302 Adding new stuff, and trying to incorporate stuff from old faq.
1304 Revision 1.12 2002/03/11 20:13:21 swa
1307 Revision 1.11 2002/03/11 18:42:27 swa
1310 Revision 1.10 2002/03/11 13:13:27 swa
1311 correct feedback channels
1313 Revision 1.9 2002/03/10 23:34:04 swa
1314 more info on not hiding ip address
1316 Revision 1.8 2002/03/09 15:55:48 swa
1317 added default config section
1319 Revision 1.7 2002/03/07 18:16:55 swa
1322 Revision 1.6 2002/03/07 13:16:31 oes
1323 Committing changes by Stefan
1325 Revision 1.5 2002/03/02 15:50:04 swa
1326 2.9.11 version. more input for docs.
1328 Revision 1.4 2002/02/24 14:34:24 jongfoster
1329 Formatting changes. Now changing the doctype to DocBook XML 4.1
1330 will work - no other changes are needed.
1332 Revision 1.3 2001/09/23 10:13:48 swa
1333 upload process established. run make webserver and
1334 the documentation is moved to the webserver. documents
1335 are now linked correctly.
1337 Revision 1.2 2001/09/13 15:20:17 swa
1338 merged standards into developer manual
1340 Revision 1.1 2001/09/12 15:36:41 swa
1341 source files for junkbuster documentation
1343 Revision 1.3 2001/09/10 17:43:59 swa
1344 first proposal of a structure.
1346 Revision 1.2 2001/06/13 14:28:31 swa
1347 docs should have an author.
1349 Revision 1.1 2001/06/13 14:20:37 swa
1350 first import of project's documentation for the webserver.