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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
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>Troubleshooting</TITLE
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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="TROUBLE"
>5. Troubleshooting</A
></H1
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="AEN1084"
>5.1. I cannot connect to any websites. Or, I am getting
<SPAN
CLASS="QUOTE"
>"connection refused"</SPAN
> message with every web page. Why?</A
></H3
><P
> There are several possibilities:</P
><P
><P
></P
><UL
><LI
><P
><SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> is not running. Solution: verify
that <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> is installed correctly, has not crashed, and is indeed running.
Turn on <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
> logging, and look at the logs to see what they say.</P
></LI
><LI
><P
>Or your browser is configured for a different port than what
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> is using. Solution: verify that <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>
and your browser are set to the same port (<TT
CLASS="LITERAL"
>listen-address</TT
>).</P
></LI
><LI
><P
>Or if using a forwarding rule, you have a configuration problem or a
problem with a host in the forwarding chain. Solution: temporarily alter your
configuration and take the forwarders out of the equation.</P
></LI
><LI
><P
> Or you have a firewall that is interfering and blocking you. Solution:
try disabling or removing the firewall as a simple test.
</P
></LI
></UL
></P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="ERROR503"
>5.2. Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</A
></H3
><P
> More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
been reported to cause this symptom -- even if not running! The solution is
to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
something better behaved in its place. Other personal firewall type products
may cause similar type problems if not configured correctly.
</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="AEN1107"
>5.3. I just added a new rule, but the steenkin ad is
still getting through. How?</A
></H3
><P
> If the ad had been displayed before you added its URL, it will probably be
held in the browser's cache for some time, so it will be displayed without
the need for any request to the server, and <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>
will not be involved. Flush the browser's caches, and then try again.</P
><P
> If this doesn't help, you probably have an error in the rule you
applied. Try pasting the full URL of the offending ad into <A
HREF="http://config.privoxy.org/show-url-info"
TARGET="_top"
>http://config.privoxy.org/show-url-info</A
>
and see if it really matches your new rule. Blocking ads is like blocking
spam: a lot of tinkering is required to stay ahead of the game. And
remember you need to block the URL of the ad in question, which may be
entirely different from the site URL itself. Most ads are hosted on different
servers than the main site itself. If you right-click on the ad, you should
be able to get all the relevant information you need. Alternately, you can
find the correct URL by looking at <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
> logs
(you may need to enable logging in the main config file if its disabled).</P
><P
> Below is a slightly modified real-life log snippet that originates with one
requested URL: <TT
CLASS="LITERAL"
>www.example.com</TT
> (name of site was changed
for this example, the number of requests is real). You can see in this the
complexity of what goes into making up this one <SPAN
CLASS="QUOTE"
>"page"</SPAN
>. There
are eight different domains involved here, with thirty two separate URLs
requested in all, making up all manner of images, Shockwave Flash,
JavaScript, CSS stylesheets, scripts, and other related content. Some of this
content is obviously <SPAN
CLASS="QUOTE"
>"good"</SPAN
> or <SPAN
CLASS="QUOTE"
>"bad"</SPAN
>, but not all.
Many of the more questionable looking requests, are going to outside domains
that seem to be identifying themselves with suspicious looking names, making
our job a little easier. <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> has <SPAN
CLASS="QUOTE"
>"crunched"</SPAN
> (meaning caught
and BLOCKED) quite a few items in this example, but perhaps missed a few as well. </P
><P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
>Request: www.example.com/
Request: www.example.com/favicon.ico
Request: img.example.com/main.css
Request: img.example.com/sr.js
Request: example.betamarker.com/example.html
Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
Request: img.example.com/pb.png
Request: www.google-analytics.com/urchin.js crunch! (Blocked)
Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
Request: img.example.com/p.gif
Request: www.popuptraffic.com/assign.php?l=example&#38;mode=behind crunch! (Blocked)
Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&#38;tmpl=PBa.tmpl crunch! (Blocked)
Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
Request: www.adtrak.net/adx.js crunch! (Blocked)
Request: img.example.com/hbg.gif
Request: img.example.com/example.jpg
Request: img.example.com/mt.png
Request: img.example.com/mm.png
Request: img.example.com/mb.png
Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&#38;tmpl=Ua.tmp crunch! (Blocked)
Request: www.example.com/tracker.js
Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
Request: www.adtrak.net/adjs.php?n=020548130&#38;what=zone:61 crunch! (Blocked)
Request: www.adtrak.net/adjs.php?n=463594413&#38;what=zone:58&#38;source=Ua crunch! (Blocked)
Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
Request: mmm.elitemediagroup.net/install.php?allowpop=no&#38;popupmincook=0&#38;allowsp2=1 crunch! (Blocked)
Request: www.example.com/tracker.js?screen=1400x1050&#38;win=962x693
Request: www.adtrak.net/adlog.php?bannerid=1309&#38;clientid=439&#38;zoneid=61 crunch! (Blocked)
Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&#38;si
Request: 66.70.21.80/img/pixel.gif
Request: www.adtrak.net/adlog.php?bannerid=1309&#38;clientid=439&#38;zoneid=58&#38;source=Ua&#38;block=86400 crunch! (Blocked)
Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&#38;si=Ua</PRE
></TD
></TR
></TABLE
></P
><P
> Despite 12 out of 32 requests being blocked, the page looked, and seemed to
behave perfectly <SPAN
CLASS="QUOTE"
>"normal"</SPAN
> (minus some ads, of course).</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="BADSITE"
>5.4. One of my favorite sites does not work with Privoxy.
What can I do?</A
></H3
><P
> First verify that it is indeed a <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> problem,
by toggling off <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> through <A
HREF="http://config.privoxy.org/toggle"
TARGET="_top"
>http://config.privoxy.org/toggle</A
>
(the toggle feature may need to be enabled in the main
<TT
CLASS="FILENAME"
>config</TT
>),
and then shift-reloading the problem page (i.e. holding down the shift key
while clicking reload. Alternatively, flush your browser's disk and memory
caches).</P
><P
> If the problem went away, we know we have a configuration related problem.
Now go to <A
HREF="http://config.privoxy.org/show-url-info"
TARGET="_top"
>http://config.privoxy.org/show-url-info</A
>
and paste the full URL of the page in question into the prompt. See which
actions are being applied to the URL, and which matches in which actions
files are responsible for that. It might be helpful also to look at your logs
for this site too, to see what else might be happening (note: logging may need
to be enabled in the main config file). Many sites are
complex and require a number of related pages to help present their content.
Look at what else might be used by the page in question, and what of that
might be <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>required</I
></SPAN
>.
Now, armed with this information, go to
<A
HREF="http://config.privoxy.org/show-status"
TARGET="_top"
>http://config.privoxy.org/show-status</A
>
and select the appropriate actions files for editing. </P
><P
> You can now either look for a section which disables the actions that
you suspect to cause the problem and add a pattern for your site there,
or make up a completely new section for your site. In any case, the recommended
way is to disable only the prime suspect, reload the problem page, and only
if the problem persists, disable more and more actions until you have
identified the culprit. You may or may not want to turn the other actions
on again. Remember to flush your browser's caches in between any such changes!</P
><P
> Alternately, if you are comfortable with a text editor, you can accomplish
the same thing by editing the appropriate actions file. Probably the easiest
way to deal with such problems when editing by hand is to add your
site to a <TT
CLASS="LITERAL"
>{ fragile }</TT
> section in <TT
CLASS="FILENAME"
>user.action</TT
>,
which is an alias that turns off most <SPAN
CLASS="QUOTE"
>"dangerous"</SPAN
>
actions, but is also likely to turn off more actions then needed, and thus lower
your privacy and protection more than necessary, </P
><P
> Troubleshooting actions is discussed in more detail in the <A
HREF="../user-manual/appendix.html#ACTIONSANAT"
TARGET="_top"
>User Manual appendix,
Troubleshooting: the Anatomy of an Action</A
>.
There is also an <A
HREF="../user-manual/actions-file.html#ACT-EXAMPLES"
TARGET="_top"
>actions tutorial</A
>
with general configuration information and examples.</P
><P
> As a last resort, you can always see if your browser has a setting that will
bypass the proxy setting for selective sites. Modern browsers can do this.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="DUN"
>5.5. After installing Privoxy, I have to log in
every time I start IE. What gives?</A
></H3
><P
> This is a quirk that effects the installation of
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>, in conjunction with Internet Explorer and
Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
appear to be corrupted or invalid DUN settings, or passwords.</P
><P
> When setting up an NT based Windows system with
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> you may find that things do not seem to be
doing what you expect. When you set your system up you will probably have set
up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
logged in with administrator privileges. You will probably have made this DUN
connection available to other accounts that you may have set-up on your
system. E.g. Mum or Dad sets up the system and makes accounts suitably
configured for the kids.</P
><P
> When setting up <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> in this environment you
will have to alter the proxy set-up of Internet Explorer (IE) for the
specific DUN connection on which you wish to use
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>. When you do this the ICS DUN set-up
becomes user specific. In this instance you will see no difference if you
change the DUN connection under the account used to set-up the connection.
However when you do this from another user you will notice that the DUN
connection changes to make available to "Me only". You will also find that
you have to store the password under each different user!</P
><P
> The reason for this is that each user's set-up for IE is user specific. Each
set-up DUN connection and each LAN connection in IE store the settings for
each user individually. As such this enforces individual configurations
rather than common ones. Hence the first time you use a DUN connection after
re-booting your system it may not perform as you expect, and prompt you for
the password. Just set and save the password again and all should be OK.</P
><P
>[Thanks to Ray Griffith for this submission.]</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="FTP"
>5.6. I cannot connect to any FTP sites. Privoxy
is blocking me.</A
></H3
><P
> <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> cannot act as a proxy for FTP traffic,
so do not configure your browser to use <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>
as an FTP proxy. The same is true for <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>any protocol other than HTTP
or HTTPS (SSL)</I
></SPAN
>.
</P
><P
> Most browsers understand FTP as well as HTTP. If you connect to a site, with
a URL like <TT
CLASS="LITERAL"
>ftp://ftp.example.com</TT
>, your browser is making
an FTP connection, and not a HTTP connection. So while your browser may
speak FTP, <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> does not, and cannot proxy
such traffic.
</P
><P
> To complicate matters, some systems may have a generic <SPAN
CLASS="QUOTE"
>"proxy"</SPAN
>
setting, which will enable various protocols, including
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>both</I
></SPAN
> HTTP and FTP proxying! So it is possible to
accidentally enable FTP proxying in these cases. And of course, if this
happens, <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> will indeed cause problems since
it does not know FTP. Newer version will give a sane error
message if a FTP connection is attempted. Just disable the FTP setting
and all will be well again.
</P
><P
> Will <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> ever proxy FTP traffic? Unlikely.
There just is not much reason, and the work to make this happen is more than
it may seem.
</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="MACOSXIE"
>5.7. In Mac OS X, I can't configure Microsoft Internet Explorer to use
Privoxy as the HTTP proxy.</A
></H3
><P
> Microsoft Internet Explorer (in versions like 5.1) respects system-wide
network settings. In order to change the HTTP proxy, open System
Preferences, and click on the Network icon. In the settings pane that
comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
is checked and enter <TT
CLASS="LITERAL"
>127.0.0.1</TT
> in the entry field.
Enter <TT
CLASS="LITERAL"
>8118</TT
> in the Port field. The next time you start
IE, it should reflect these values.
</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="MACOSXUNINSTALL"
>5.8. In Mac OS X, I dragged the Privoxy folder to the trash in order to
uninstall it. Now the finder tells me I don't have sufficient privileges to
empty the trash.</A
></H3
><P
> Note: This ONLY applies to privoxy 3.0.6 and earlier.
</P
><P
> Just dragging the <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> folder to the trash is
not enough to delete it. <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> supplies an
<SPAN
CLASS="APPLICATION"
>uninstall.command</SPAN
> file that takes care of
these details. Open the trash, drag the <SPAN
CLASS="APPLICATION"
>uninstall.command</SPAN
>
file out of the trash and double-click on it. You will be prompted for
confirmation and the administration password.
</P
><P
> The trash may still appear full after this command; emptying the trash
from the desktop should make it appear empty again.
</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="MACOSXIMAGES"
>5.9. In Mac OS X Panther (10.3), images often fail to load and/or I
experience random delays in page loading. I'm using
<TT
CLASS="LITERAL"
>localhost</TT
> as my browser's proxy setting.</A
></H3
><P
> We believe this is due to an IPv6-related bug in Mac OS X, but don't fully
understand the issue yet. In any case, changing the proxy setting to
<TT
CLASS="LITERAL"
>127.0.0.1</TT
> instead of <TT
CLASS="LITERAL"
>localhost</TT
>
works around the problem.
</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="BLANKPAGE"
>5.10. I get a completely blank page at one site. <SPAN
CLASS="QUOTE"
>"View Source"</SPAN
>
shows only: <SPAN
CLASS="MARKUP"
>&#60;html&#62;&#60;body&#62;&#60;/body&#62;&#60;/html&#62;</SPAN
>. Without
Privoxy the page loads fine.</A
></H3
><P
> Chances are that the site suffers from a bug in
<A
HREF="http://www.php.net/"
TARGET="_top"
><SPAN
CLASS="APPLICATION"
>PHP</SPAN
></A
>,
which results in empty pages being sent if the client explicitly requests
an uncompressed page, like <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> does.
This bug has been fixed in PHP 4.2.3.
</P
><P
> To find out if this is in fact the source of the problem, try adding
the site to a <TT
CLASS="LITERAL"
>-prevent-compression</TT
> section in
<TT
CLASS="FILENAME"
>user.action</TT
>:
</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
> # Make exceptions for ill-behaved sites:
#
{-prevent-compression}
.example.com</PRE
></TD
></TR
></TABLE
><P
> If that works, you may also want to report the problem to the
site's webmasters, telling them to use zlib.output_compression
instead of ob_gzhandler in their PHP applications (workaround)
or upgrade to PHP 4.2.3 or later (fix).
</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="NOHOSTNAME"
>5.11. My logs show many <SPAN
CLASS="QUOTE"
>"Unable to get my own hostname"</SPAN
> lines.
Why?</A
></H3
><P
> <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> tries to get the hostname of the system
its running on from the IP address of the system interface it is bound to
(from the <TT
CLASS="FILENAME"
>config</TT
> file
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>listen-address</I
></SPAN
> setting). If the system cannot supply
this information, <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> logs this condition. </P
><P
> Typically, this would be considered a minor system configuration error. It is
not a fatal error to <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> however, but may
result in a much slower response from <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> on
some platforms due to DNS timeouts.</P
><P
> This can be caused by a problem with the local <TT
CLASS="FILENAME"
>hosts</TT
>
file. If this file has been changed from the original, try reverting it to
see if that helps. Make sure whatever name(s) are used for the local system,
that they resolve both ways.</P
><P
> You should also be able to work around the problem with the
<A
HREF="../user-manual/config.html#HOSTNAME"
TARGET="_top"
>hostname option</A
>.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="INUSE"
>5.12. When I try to launch Privoxy, I get an
error message <SPAN
CLASS="QUOTE"
>"port 8118 is already in use"</SPAN
> (or similar wording).
Why?</A
></H3
><P
> Port 8118 is <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
> default TCP
<SPAN
CLASS="QUOTE"
>"listening"</SPAN
> port. Typically this message would mean that there
is already one instance of <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> running, and
your system is actually trying to start a second
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> on the same port, which will not work.
(You can have multiple instances but they must be assigned different ports.)
How and why this might happen varies from platform to platform, but you need
to check your installation and start-up procedures.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="DEMORONIZER"
>5.13. Pages with UTF-8 fonts are garbled.</A
></H3
><P
> This is caused by the <SPAN
CLASS="QUOTE"
>"demoronizer"</SPAN
> filter. You should either
upgrade <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>, or at least upgrade to the most
recent <TT
CLASS="FILENAME"
>default.action</TT
> file available from <A
HREF="http://sourceforge.net/project/showfiles.php?group_id=11118"
TARGET="_top"
>SourceForge</A
>.
Or you can simply disable the demoronizer filter.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="DEMORONIZER2"
>5.14. Why are binary files (such as images) corrupted when Privoxy
is used?</A
></H3
><P
> This may also be caused by the <SPAN
CLASS="QUOTE"
>"demoronizer"</SPAN
> filter,
in conjunction with a web server that is misreporting the content type. Binary
files are exempted from <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
> filtering
(unless the web server by mistake says the file is something else). Either
upgrade <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>, or go to the most recent
<TT
CLASS="FILENAME"
>default.action</TT
> file available from <A
HREF="http://sourceforge.net/project/showfiles.php?group_id=11118"
TARGET="_top"
>SourceForge</A
>.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="DEMORONIZER3"
>5.15. What is the <SPAN
CLASS="QUOTE"
>"demoronizer"</SPAN
> and why is it there?</A
></H3
><P
> The original demoronizer was a Perl script that cleaned up HTML pages which
were created with certain Microsoft products. MS has used proprietary extensions
to standardized font encodings (ISO 8859-1), which has caused problems for pages
that are viewed with non-Microsoft products (and are expecting to see a
standard set of fonts). The demoronizer corrected these errors so the pages
displayed correctly. <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> borrowed from this
script, introducing a filter based on the original demoronizer, which in turn could
correct these errors on the fly. </P
><P
> But this is only needed in some situations, and will cause serious problems in some
other situations.</P
><P
> If you are using Microsoft products, you do not need it. If you need to view
pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
cause corruption of the fonts, and thus <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>should not be on</I
></SPAN
>.</P
><P
> On the other hand, if you use non-Microsoft products, and you occasionally
notice weird characters on pages, you might want to try it.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="WINDOWOPEN"
>5.16. Why do I keep seeing <SPAN
CLASS="QUOTE"
>"PrivoxyWindowOpen()"</SPAN
> in raw source code?</A
></H3
><P
> <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> is attempting to disable malicious
<A
HREF="http://en.wikipedia.org/wiki/Javascript"
TARGET="_top"
>Javascript</A
>
in this case, with the <TT
CLASS="LITERAL"
>unsolicited-popups</TT
>
filter. <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> cannot tell very well
<SPAN
CLASS="QUOTE"
>"good"</SPAN
> code snippets from <SPAN
CLASS="QUOTE"
>"bad"</SPAN
> code snippets.</P
><P
> If you see this in HTML source, and the page displays without problems, then
this is good, and likely some pop-up window was disabled. If you see this
where it is causing a problem, such as a downloaded program source code file,
then you should set an exception for this site or page such that the
integrity of the page stays in tact by disabling all filtering.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="DNSERRORS"
>5.17. I am getting too many DNS errors like <SPAN
CLASS="QUOTE"
>"404 No Such Domain"</SPAN
>. Why
can't Privoxy do this better?</A
></H3
><P
> There are potentially several factors here. First of all, the DNS resolution
is done by the underlying operating system -- not
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> itself. <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>
merely initiates the process and hands it off, and then later reports
whatever the outcome was and tries to give a coherent message if there seems
to be a problem. In some cases, this might otherwise be mitigated by the
browser itself which might try some work-arounds and alternate approaches (e.g
adding <SPAN
CLASS="QUOTE"
>"www."</SPAN
> to the URL).</P
><P
> In other cases, if <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> is being chained
with another proxy, this could complicate the issue, and cause undue
delays and timeouts. In the case of a <SPAN
CLASS="QUOTE"
>"socks4a"</SPAN
> proxy, the socks
server handles all the DNS. <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> would just be
the <SPAN
CLASS="QUOTE"
>"messenger"</SPAN
> which is reporting whatever problem occurred
downstream, and not the root cause of the error.</P
><P
> In any case, versions newer than 3.0.3 include various improvements to help
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> better handle these cases.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="ALLCPU"
>5.18. At one site Privoxy just hangs, and starts taking
all CPU. Why is this?</A
></H3
><P
> This is probably a manifestation of the <SPAN
CLASS="QUOTE"
>"100% cpu"</SPAN
> problem that
occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
are in the raw HTML source of the page, and the browser just ignores them. But the
pattern matching in <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
> page filtering
mechanism is trying to match against absurdly long strings and this becomes
very CPU-intensive, taking a long, long time to complete.</P
><P
> Until a better solution comes along, disable filtering on these pages,
particularly the <TT
CLASS="LITERAL"
>js-annoyances</TT
> and
<TT
CLASS="LITERAL"
>unsolicited-popups</TT
> filters. If you run into this problem
with a recent <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> version, please send a problem report.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="SLOWCRAWL"
>5.19. I just installed Privoxy, and all my
browsing has slowed to a crawl. What gives?</A
></H3
><P
> This should not happen, and for the overwhelming number of users world-wide,
it does not happen. I would suspect some inadvertent interaction of software
components such as anti-virus software, spyware protectors, personal
firewalls or similar components. Try disabling (or uninstalling) these one
at a time and see if that helps. Either way, if you are using a
recent <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> version, please report the problem.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="PREVENTCOMP"
>5.20. Why do my filters work on some sites but not on others?</A
></H3
><P
> It's probably due to compression. It is a common practice for web servers to
send their content <SPAN
CLASS="QUOTE"
>"compressed"</SPAN
> in order to speed things up, and
then let the browser <SPAN
CLASS="QUOTE"
>"uncompress"</SPAN
> them. When compiled with zlib support
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> can decompress content before filtering, otherwise you may want to enable
<A
HREF="../user-manual/actions-file.html#PREVENT-COMPRESSION"
TARGET="_top"
>prevent-compression</A
>.</P
><P
> As of <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> 3.0.9, zlib support is enabled in the default builds.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="SSL-WARNINGS"
>5.21. On some HTTPS sites my browser warns me about unauthenticated content,
the URL bar doesn't get highlighted and the lock symbol appears to be broken.
What's going on?</A
></H3
><P
> Probably the browser is requesting ads through HTTPS and <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>
is blocking the requests. Privoxy's error messages are delivered
unencrypted and while it's obvious for the browser that the HTTPS
request is already blocked by the proxy, some warn about unauthenticated
content anyway.</P
><P
> To work around the problem you can redirect those requests to an invalid
local address instead of blocking them. While the redirects aren't
encrypted either, many browsers don't care. They simply follow the
redirect, fail to reach a server and display an error message instead
of the ad.</P
><P
> To do that, enable logging to figure out which requests get blocked by
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> and add the hosts (no path patterns) to a section like this:</P
><P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
>{+redirect{http://127.0.0.1:0/} -block -limit-connect}
.ivwbox.de:443/</PRE
></TD
></TR
></TABLE
></P
><P
> Additionally you have to configure your browser to contact
<SPAN
CLASS="QUOTE"
>"127.0.0.1:0"</SPAN
> directly (instead of through <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>).</P
><P
> To add a proxy exception in <SPAN
CLASS="APPLICATION"
>Mozilla Firefox</SPAN
>
open the <SPAN
CLASS="QUOTE"
>"Preferences"</SPAN
>, click the <SPAN
CLASS="QUOTE"
>"Settings"</SPAN
>
button located on the <SPAN
CLASS="QUOTE"
>"Network"</SPAN
> tab in the <SPAN
CLASS="QUOTE"
>"Advanced"</SPAN
>
section, and add <SPAN
CLASS="QUOTE"
>"127.0.0.1:0"</SPAN
> in the <SPAN
CLASS="QUOTE"
>"No Proxy for:"</SPAN
>
field.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="SE-LINUX"
>5.22. I get selinux error messages. How can I fix this?</A
></H3
><P
> Please report the problem to the creator of your selinux policies.</P
><P
> The problem is that some selinux policy writers aren't familiar
with the application they are trying to <SPAN
CLASS="QUOTE"
>"secure"</SPAN
> and
thus create policies that make no sense.</P
><P
> In <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
> case the problem usually
is that the policy only allows outgoing connections for certain
destination ports (e.g. 80 and 443). While this may cover the
standard ports, websites occasionally use other ports as well.
This isn't a security problem and therefore <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
>
default configuration doesn't block these requests.</P
><P
> If you really want to block these ports (and don't be able
to load websites that don't use standard ports), you should
configure Privoxy to block these ports as well, so it doesn't
trigger the selinux warnings.</P
></DIV
><DIV
CLASS="SECT2"
><H3
CLASS="SECT2"
><A
NAME="GENTOO-RICERS"
>5.23. I compiled <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> with Gentoo's portage and it appears to be very slow. Why?</A
></H3
><P
> Probably you unintentionally compiled <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> without threading support
in which case requests have to be serialized and only one can be served
at the same time.</P
><P
> Check your <SPAN
CLASS="QUOTE"
>"USE"</SPAN
> flags and make sure they include
<SPAN
CLASS="QUOTE"
>"threads"</SPAN
>. If they don't, add the flag and rebuild <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>.</P
><P
> If you compiled <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
> with threading support (on POSIX-based systems),
the <SPAN
CLASS="QUOTE"
>"Conditional #defines"</SPAN
> section on <A
HREF="http://config.privoxy.org/show-status"
TARGET="_top"
>http://config.privoxy.org/show-status</A
>
will list <SPAN
CLASS="QUOTE"
>"FEATURE_PTHREAD"</SPAN
> as <SPAN
CLASS="QUOTE"
>"enabled"</SPAN
>. </P
></DIV
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