X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Fwebserver%2Ffaq%2Ftrouble.html;fp=doc%2Fwebserver%2Ffaq%2Ftrouble.html;h=c216e53a88216d0eb9fb7935be3ed00068a2dcb5;hp=2d5d3ab2797dc51d70e5a6d43697de7a398e29cb;hb=d9813d602eb59d009d10e6d3861cd99821a6db70;hpb=6b6d7c96a8e264bac0f95e4403fc728a464e11b9 diff --git a/doc/webserver/faq/trouble.html b/doc/webserver/faq/trouble.html index 2d5d3ab2..c216e53a 100644 --- a/doc/webserver/faq/trouble.html +++ b/doc/webserver/faq/trouble.html @@ -3,117 +3,86 @@ Troubleshooting - - + + - + - +
-

5. - Troubleshooting

+

5. Troubleshooting

-

5.1. I cannot connect - to any websites. Or, I am getting "connection - refused" message with every web page. Why?

+

5.1. I cannot connect to any websites. Or, I am getting + "connection refused" message with every web page. Why?

There are several possibilities:

-

5.2. Why am I - getting a 503 Error (WSAECONNREFUSED) on every page?

-

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 +

5.2. Why am I getting a 503 Error (WSAECONNREFUSED) on every + page?

+

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.

-

5.3. I just added a - new rule, but the steenkin ad is still getting through. How?

-

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 - Privoxy will not be involved. Flush - the browser's caches, and then try again.

-

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 http://config.privoxy.org/show-url-info 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 Privoxy's logs (you may need to enable logging in - the main config file if its disabled).

-

Below is a slightly modified real-life log snippet that originates - with one requested URL: www.example.com (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 - "page". 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 - "good" or "bad", - 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. Privoxy has "crunched" - (meaning caught and BLOCKED) quite a few items in this example, but - perhaps missed a few as well.

+

5.3. I just added a new rule, but the steenkin ad is still + getting through. How?

+

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 Privoxy will not be involved. Flush the browser's caches, and then try again.

+

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 http://config.privoxy.org/show-url-info 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 Privoxy's logs (you may need to enable logging in the main config file if its disabled).

+

Below is a slightly modified real-life log snippet that originates with one requested URL: www.example.com (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 "page". 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 "good" or "bad", 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. Privoxy has + "crunched" (meaning caught and BLOCKED) quite a few items in this example, but perhaps + missed a few as well.

@@ -153,501 +122,391 @@ Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
-

Despite 12 out of 32 requests being blocked, the page looked, and - seemed to behave perfectly "normal" (minus - some ads, of course).

+

Despite 12 out of 32 requests being blocked, the page looked, and seemed to behave perfectly "normal" (minus some ads, of course).

-

5.4. One of my - favorite sites does not work with Privoxy. What can I do?

-

First verify that it is indeed a Privoxy problem, by toggling off Privoxy through http://config.privoxy.org/toggle (the toggle feature may - need to be enabled in the main config), 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).

-

If the problem went away, we know we have a configuration related - problem. Now go to http://config.privoxy.org/show-url-info 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 required. Now, armed with this information, go to - http://config.privoxy.org/show-status and select the +

5.4. One of my favorite sites does not work with Privoxy. What + can I do?

+

First verify that it is indeed a Privoxy problem, by toggling off + Privoxy through http://config.privoxy.org/toggle (the toggle feature may need to be enabled in the main config), 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).

+

If the problem went away, we know we have a configuration related problem. Now go to http://config.privoxy.org/show-url-info 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 required. Now, armed with this information, go to http://config.privoxy.org/show-status and select the appropriate actions files for editing.

-

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!

-

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 { fragile } - section in user.action, which is an alias - that turns off most "dangerous" actions, but - is also likely to turn off more actions then needed, and thus lower - your privacy and protection more than necessary,

-

Troubleshooting actions is discussed in more detail in the User Manual - appendix, Troubleshooting: the Anatomy of an Action. There is also - an actions tutorial with general configuration information and - examples.

-

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.

+

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!

+

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 { fragile } section in user.action, which is an + alias that turns off most "dangerous" actions, but is also likely to turn off more + actions then needed, and thus lower your privacy and protection more than necessary,

+

Troubleshooting actions is discussed in more detail in the User Manual appendix, Troubleshooting: the Anatomy of an Action. There is also an actions tutorial with general configuration + information and examples.

+

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.

-

5.5. After installing Privoxy, - I have to log in every time I start IE. What gives?

-

This is a quirk that affects the installation of Privoxy, 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.

-

When setting up an NT based Windows system with Privoxy 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.

-

When setting up Privoxy 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 - Privoxy. 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!

-

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.

+

5.5. After installing Privoxy, I have to log in every time I start IE. + What gives?

+

This is a quirk that affects the installation of Privoxy, 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.

+

When setting up an NT based Windows system with Privoxy 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.

+

When setting up Privoxy 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 Privoxy. 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!

+

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.

[Thanks to Ray Griffith for this submission.]

-

5.6. I cannot connect to any - FTP sites. Privoxy is blocking me.

-

Privoxy cannot act as a proxy for - FTP traffic, so do not configure your browser to use Privoxy as an FTP proxy. The same is true for - any protocol other than HTTP - or HTTPS (SSL).

-

Most browsers understand FTP as well as HTTP. If you connect to a - site, with a URL like ftp://ftp.example.com, - your browser is making an FTP connection, and not a HTTP connection. So - while your browser may speak FTP, Privoxy does not, and cannot proxy such +

5.6. I cannot connect to any FTP sites. Privoxy is blocking me.

+

Privoxy cannot act as a proxy for FTP traffic, so do not configure your + browser to use Privoxy as an FTP proxy. The same is true for any protocol other than HTTP or HTTPS (SSL).

+

Most browsers understand FTP as well as HTTP. If you connect to a site, with a URL like ftp://ftp.example.com, your browser is making an FTP connection, and not a HTTP connection. So + while your browser may speak FTP, Privoxy does not, and cannot proxy such traffic.

-

To complicate matters, some systems may have a generic "proxy" setting, which will enable various protocols, - including both - HTTP and FTP proxying! So it is possible to accidentally enable FTP - proxying in these cases. And of course, if this happens, Privoxy 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 +

To complicate matters, some systems may have a generic "proxy" setting, which will + enable various protocols, including both HTTP and FTP + proxying! So it is possible to accidentally enable FTP proxying in these cases. And of course, if this happens, + Privoxy 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.

-

Will Privoxy ever proxy FTP - traffic? Unlikely. There just is not much reason, and the work to make - this happen is more than it may seem.

+

Will Privoxy ever proxy FTP traffic? Unlikely. There just is not much reason, + and the work to make this happen is more than it may seem.

-

5.7. In Mac OS X, I - can't configure Microsoft Internet Explorer to use Privoxy as the HTTP - proxy.

-

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 127.0.0.1 in the - entry field. Enter 8118 in the Port field. The - next time you start IE, it should reflect these values.

+

5.7. In Mac OS X, I can't configure Microsoft Internet + Explorer to use Privoxy as the HTTP proxy.

+

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 127.0.0.1 in the entry field. Enter 8118 in the Port field. The next time + you start IE, it should reflect these values.

-

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.

+

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.

Note: This ONLY applies to privoxy 3.0.6 and earlier.

-

Just dragging the Privoxy folder to - the trash is not enough to delete it. Privoxy supplies an uninstall.command file that takes care of these - details. Open the trash, drag the uninstall.command file out of the trash and - double-click on it. You will be prompted for confirmation and the - administration password.

-

The trash may still appear full after this command; emptying the - trash from the desktop should make it appear empty again.

+

Just dragging the Privoxy folder to the trash is not enough to delete it. + Privoxy supplies an uninstall.command file that + takes care of these details. Open the trash, drag the uninstall.command file out + of the trash and double-click on it. You will be prompted for confirmation and the administration password.

+

The trash may still appear full after this command; emptying the trash from the desktop should make it appear + empty again.

-

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 localhost as my browser's proxy setting.

-

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 127.0.0.1 instead of 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 localhost as my + browser's proxy setting. +

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 127.0.0.1 instead of localhost works around the problem.

-

5.10. I just upgraded to Mac OS X 10.9 - (Mavericks) and now Privoxy has - stopped working.

-

The upgrade process to Mac OS X Mavericks (10.9) from an earlier - version of OS X deletes all user accounts that are either not part of - OS X itself or are not interactive user accounts (ones you log in - with). Since, for the sake of security, Privoxy runs as a non-privileged user that is - created by its installer (_privoxy), it can no longer start up once - that account gets deleted. The solution is to perform a complete - uninstall using the supplied uninstall.command script (either back up your - configuration files or select to not have the uninstaller remove them - when it prompts you) and then reinstall Privoxy using the installer package and merge in - your configuration.

+

5.10. I just upgraded to Mac OS X + 10.9 (Mavericks) and now Privoxy has stopped working.

+

The upgrade process to Mac OS X Mavericks (10.9) from an earlier version of OS X deletes all user accounts + that are either not part of OS X itself or are not interactive user accounts (ones you log in with). Since, for + the sake of security, Privoxy runs as a non-privileged user that is created by + its installer (_privoxy), it can no longer start up once that account gets deleted. The solution is to perform a + complete uninstall using the supplied uninstall.command script (either back up + your configuration files or select to not have the uninstaller remove them when it prompts you) and then + reinstall Privoxy using the installer package and merge in your + configuration.

-

5.11. My logs - show many "Unable to get my own hostname" - lines. Why?

-

Privoxy 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 config - file listen-address setting). If the system cannot - supply this information, Privoxy logs - this condition.

-

Typically, this would be considered a minor system configuration - error. It is not a fatal error to Privoxy however, but may result in a much slower - response from Privoxy on some - platforms due to DNS timeouts.

-

This can be caused by a problem with the local hosts 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.

-

You should also be able to work around the problem with the hostname - option.

+

5.11. My logs show many "Unable to get + my own hostname" lines. Why?

+

Privoxy 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 config file listen-address setting). If the system cannot supply this information, + Privoxy logs this condition.

+

Typically, this would be considered a minor system configuration error. It is not a fatal error to + Privoxy however, but may result in a much slower response from Privoxy on some platforms due to DNS timeouts.

+

This can be caused by a problem with the local hosts 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.

+

You should also be able to work around the problem with the hostname option.

-

5.12. When I try to launch - Privoxy, I get an error message "port 8118 is - already in use" (or similar wording). Why?

-

Port 8118 is Privoxy's default TCP - "listening" port. Typically this message - would mean that there is already one instance of Privoxy running, and your system is actually - trying to start a second Privoxy 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.

+

5.12. When I try to launch Privoxy, I get an error message + "port 8118 is already in use" (or similar wording). Why?

+

Port 8118 is Privoxy's default TCP "listening" + port. Typically this message would mean that there is already one instance of Privoxy running, and your system is actually trying to start a second Privoxy 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.

-

5.13. Pages - with UTF-8 fonts are garbled.

-

This may be the result of an overly aggressive filter. The filters - that are enabled in the default configuration aren't expected to cause - problems like this. If you enabled the "demoronizer" filter, please try temporarily disabling - it.

-

If that doesn't help, temporarily disable all filters to see if - another filter could be the culprit. If the problem disappears, enable - the filters one by one, until the problem reappears and the offending - filter is found.

-

Once the problem-causing filter is known, it can be fixed or - disabled.

-

Upgrading Privoxy, or going to the - most recent default.action file available - from SourceForge might be worth a try, too.

+

5.13. Pages with UTF-8 fonts are garbled.

+

This may be the result of an overly aggressive filter. The filters that are enabled in the default + configuration aren't expected to cause problems like this. If you enabled the "demoronizer" filter, please try temporarily disabling it.

+

If that doesn't help, temporarily disable all filters to see if another filter could be the culprit. If the + problem disappears, enable the filters one by one, until the problem reappears and the offending filter is + found.

+

Once the problem-causing filter is known, it can be fixed or disabled.

+

Upgrading Privoxy, or going to the most recent default.action file available from SourceForge might be worth a + try, too.

-

5.14. Why - are binary files (such as images) corrupted when Privoxy is - used?

-

This may also be caused by an (overly aggressive filter in conjunction - with a web server that is misreporting the content type. By default - binary files are exempted from Privoxy's filtering (unless the web server by - mistake says the file is something else).

+

5.14. Why are binary files (such as images) corrupted + when Privoxy is used?

+

This may also be caused by an (overly aggressive filter in conjunction + with a web server that is misreporting the content type. By default binary files are exempted from Privoxy's filtering (unless the web server by mistake says the file is something else).

-

5.15. What - is the "demoronizer" and why is it - there?

-

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. - Privoxy borrowed from this script, - introducing a filter based on the original demoronizer, which in turn - could correct these errors on the fly.

-

But this is only needed in some situations, and will cause serious - problems in some other situations.

-

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 should not be on.

-

On the other hand, if you use non-Microsoft products, and you - occasionally notice weird characters on pages, you might want to try - it.

+

5.15. What is the "demoronizer" and why is it there?

+

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. Privoxy borrowed from this script, introducing a filter based on the original demoronizer, + which in turn could correct these errors on the fly.

+

But this is only needed in some situations, and will cause serious problems in some other situations.

+

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 should not be on.

+

On the other hand, if you use non-Microsoft products, and you occasionally notice weird characters on pages, + you might want to try it.

-

5.16. Why do I - keep seeing "PrivoxyWindowOpen()" in raw - source code?

-

Privoxy is attempting to disable - malicious Javascript in this case, with the unsolicited-popups filter. Privoxy cannot tell very well "good" code snippets from "bad" code snippets.

-

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.

+

5.16. Why do I keep seeing "PrivoxyWindowOpen()" in raw source code?

+

Privoxy is attempting to disable malicious Javascript in this case, with the unsolicited-popups filter. Privoxy cannot tell very well + "good" code snippets from "bad" code snippets.

+

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.

-

5.17. I am getting - too many DNS errors like "404 No Such - Domain". Why can't Privoxy do this better?

-

There are potentially several factors here. First of all, the DNS - resolution is done by the underlying operating system -- not - Privoxy itself. Privoxy 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 5.17. I am getting too many DNS errors like "404 No Such Domain". Why can't Privoxy do this better? +

There are potentially several factors here. First of all, the DNS resolution is done by the underlying + operating system -- not Privoxy itself. Privoxy + 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 "www." to the URL).

-

In other cases, if Privoxy is being - chained with another proxy, this could complicate the issue, and cause - undue delays and timeouts. In the case of a "socks4a" proxy, the socks server handles all the DNS. - Privoxy would just be the "messenger" which is reporting whatever problem occurred - downstream, and not the root cause of the error.

-

In any case, versions newer than 3.0.3 include various improvements - to help Privoxy better handle these - cases.

+

In other cases, if Privoxy is being chained with another proxy, this could + complicate the issue, and cause undue delays and timeouts. In the case of a "socks4a" + proxy, the socks server handles all the DNS. Privoxy would just be the + "messenger" which is reporting whatever problem occurred downstream, and not the root + cause of the error.

+

In any case, versions newer than 3.0.3 include various improvements to help Privoxy better handle these cases.

-

5.18. At one site - Privoxy just hangs, and starts taking all CPU. Why is this?

-

This is probably a manifestation of the "100% - cpu" 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 Privoxy's page filtering - mechanism is trying to match against absurdly long strings and this - becomes very CPU-intensive, taking a long, long time to complete.

-

Until a better solution comes along, disable filtering on these - pages, particularly the js-annoyances and - unsolicited-popups filters. If you run into - this problem with a recent Privoxy - version, please send a problem report.

+

5.18. At one site Privoxy just hangs, and starts taking all CPU. + Why is this?

+

This is probably a manifestation of the "100% cpu" 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 Privoxy's + page filtering mechanism is trying to match against absurdly long strings and this becomes very CPU-intensive, + taking a long, long time to complete.

+

Until a better solution comes along, disable filtering on these pages, particularly the js-annoyances and unsolicited-popups filters. If you run into this + problem with a recent Privoxy version, please send a problem report.

-

5.19. I just - installed Privoxy, and all my browsing has slowed to a crawl. What - gives?

-

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 Privoxy - version, please report the problem.

+

5.19. I just installed Privoxy, and all my browsing has + slowed to a crawl. What gives?

+

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 Privoxy version, please report the + problem.

-

5.20. Why do - my filters work on some sites but not on others?

-

It's probably due to compression. It is a common practice for web - servers to send their content "compressed" - in order to speed things up, and then let the browser "uncompress" them. When compiled with zlib support - Privoxy can decompress content before - filtering, otherwise you may want to enable prevent-compression.

-

As of Privoxy 3.0.9, zlib support - is enabled in the default builds.

+

5.20. Why do my filters work on some sites but not on + others?

+

It's probably due to compression. It is a common practice for web servers to send their content "compressed" in order to speed things up, and then let the browser "uncompress" them. When compiled with zlib support Privoxy can + decompress content before filtering, otherwise you may want to enable prevent-compression.

+

As of Privoxy 3.0.9, zlib support is enabled in the default builds.

-

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?

-

Probably the browser is requesting ads through HTTPS and - Privoxy 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.

-

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.

-

To do that, enable logging to figure out which requests get blocked - by Privoxy and add the hosts (no path - patterns) to a section like this:

+

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?

+

Probably the browser is requesting ads through HTTPS and Privoxy 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.

+

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.

+

To do that, enable logging to figure out which requests get blocked by Privoxy and add the hosts (no path patterns) to a section like this:

-
-            {+redirect{http://127.0.0.1:0/} -block -limit-connect}
+            
{+redirect{http://127.0.0.1:0/} -block -limit-connect}
 .ivwbox.de:443/
-

Additionally you have to configure your browser to contact - "127.0.0.1:0" directly (instead of through - Privoxy).

-

To add a proxy exception in Mozilla - Firefox open the "Preferences", click - the "Settings" button located on the - "Network" tab in the "Advanced" section, and add "127.0.0.1:0" in the "No Proxy - for:" field.

+

Additionally you have to configure your browser to contact "127.0.0.1:0" directly + (instead of through Privoxy).

+

To add a proxy exception in Mozilla Firefox open the "Preferences", click the "Settings" button located on the "Network" tab in the "Advanced" section, and add "127.0.0.1:0" in the "No Proxy for:" field.

-

5.22. I get selinux - error messages. How can I fix this?

-

Please report the problem to the creator of your selinux - policies.

-

The problem is that some selinux policy writers aren't familiar with - the application they are trying to "secure" - and thus create policies that make no sense.

-

In Privoxy's 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 Privoxy's default configuration doesn't block - these requests.

-

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.

+

5.22. I get selinux error messages. How can I fix + this?

+

Please report the problem to the creator of your selinux policies.

+

The problem is that some selinux policy writers aren't familiar with the application they are trying to + "secure" and thus create policies that make no sense.

+

In Privoxy's 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 Privoxy's default configuration doesn't block these requests.

+

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.

-

5.23. I - compiled Privoxy with Gentoo's portage - and it appears to be very slow. Why?

-

Probably you unintentionally compiled Privoxy without threading support in which case - requests have to be serialized and only one can be served at the same - time.

-

Check your "USE" flags and make sure they - include "threads". If they don't, add the - flag and rebuild Privoxy.

-

If you compiled Privoxy with - threading support (on POSIX-based systems), the "Conditional #defines" section on http://config.privoxy.org/show-status will list "FEATURE_PTHREAD" as "enabled".

+

5.23. I compiled Privoxy with Gentoo's portage and it appears to be very slow. Why?

+

Probably you unintentionally compiled Privoxy without threading support in + which case requests have to be serialized and only one can be served at the same time.

+

Check your "USE" flags and make sure they include "threads". If they don't, add the flag and rebuild Privoxy.

+

If you compiled Privoxy with threading support (on POSIX-based systems), the + "Conditional #defines" section on http://config.privoxy.org/show-status will list "FEATURE_PTHREAD" as + "enabled".

-

5.24. - What are tainted sockets and how do I prevent them?

-

Privoxy marks sockets as tainted - when it can't use them to serve additional requests. This does not - necessarily mean that something went wrong and information about - tainted sockets is only logged if connection debugging is enabled - (debug 2).

-

For example server sockets that were used for CONNECT requests - (which are used to tunnel https:// requests) are considered tainted - once the client closed its connection to Privoxy. Technically Privoxy could keep the connection to the server - open, but the server would not accept requests that do not belong to - the previous TLS/SSL session (and the client may even have terminated - the session).

-

Server sockets are also marked tainted when a client requests a - resource, but closes the connection before Privoxy has completely received (and forwarded) - the resource to the client. In this case the server would (probably) - accept additional requests, but Privoxy could not get the response without - completely reading the leftovers from the previous response.

-

These are just two examples, there are currently a bit more than 25 - scenarios in which a socket is considered tainted.

-

While sockets can also be marked tainted as a result of a technical - problem that may be worth fixing, the problem will be explicitly logged - as error.

+

5.24. What are tainted sockets and how do I + prevent them?

+

Privoxy marks sockets as tainted when it can't use them to serve additional + requests. This does not necessarily mean that something went wrong and information about tainted sockets is only + logged if connection debugging is enabled (debug 2).

+

For example server sockets that were used for CONNECT requests (which are used to tunnel https:// requests) + are considered tainted once the client closed its connection to Privoxy. + Technically Privoxy could keep the connection to the server open, but the server + would not accept requests that do not belong to the previous TLS/SSL session (and the client may even have + terminated the session).

+

Server sockets are also marked tainted when a client requests a resource, but closes the connection before + Privoxy has completely received (and forwarded) the resource to the client. In + this case the server would (probably) accept additional requests, but Privoxy + could not get the response without completely reading the leftovers from the previous response.

+

These are just two examples, there are currently a bit more than 25 scenarios in which a socket is considered + tainted.

+

While sockets can also be marked tainted as a result of a technical problem that may be worth fixing, the + problem will be explicitly logged as error.

-

5.25. After adding my custom filters, Privoxy crashes when visitting certain - websites

-

This can happen if your custom filters require more memory than - Privoxy is allowed to use. Usually the - problem is that the operating system enforces a stack size limit that - isn't sufficient.

-

Unless the problem occurs with the filters available in the default - configuration, this is not considered a Privoxy bug.

-

To prevent the crashes you can rewrite your filter to use less - ressources, increase the relevant memory limit or recompile pcre to use - less stack space. For details please see the pcrestack man page and the documentation of your operating - system.

+

5.25. After adding my custom filters, + Privoxy crashes when visitting certain websites

+

This can happen if your custom filters require more memory than Privoxy is + allowed to use. Usually the problem is that the operating system enforces a stack size limit that isn't + sufficient.

+

Unless the problem occurs with the filters available in the default configuration, this is not considered a + Privoxy bug.

+

To prevent the crashes you can rewrite your filter to use less ressources, increase the relevant memory limit + or recompile pcre to use less stack space. For details please see the pcrestack man page and the documentation of + your operating system.

+
+
+

5.26. What to do if editing the config file of + privoxy is access denied?

+

Your userid probably isn't allowed to edit the file. On Windows you can use the windows equivalent of + sudo:

+ + + + +
+
runas /user:administrator "notepad \privoxy\config.txt"
+
+

or fix the file permissions:

+ + + + +
+
C:\Privoxy>icacls config.txt
+config.txt BUILTIN\Administrators:(I)(F)
+           NT AUTHORITY\SYSTEM:(I)(F)
+           BUILTIN\Users:(I)(RX)
+           NT AUTHORITY\Authenticated Users:(I)(M)
+
+Successfully processed 1 files; Failed processing 0 files
+
+C:\Privoxy>icacls config.txt /grant Lee:F
+processed file: config.txt
+Successfully processed 1 files; Failed processing 0 files
+
+C:\Privoxy>icacls config.txt
+config.txt I3668\Lee:(F)
+           BUILTIN\Administrators:(I)(F)
+           NT AUTHORITY\SYSTEM:(I)(F)
+           BUILTIN\Users:(I)(RX)
+           NT AUTHORITY\Authenticated Users:(I)(M)
+
+Successfully processed 1 files; Failed processing 0 files
+
+C:\Privoxy>
+
+

or try to point-n-click your way through adjusting the file permissions in windows explorer.