Home | Forum | MAN Pages | Tutorials | Directory | HOWTOs | About Me | Contact
 
Squid HOWTOs
1. About Squid
2. Getting and Compiling Squid
3. Installing and Running Squid
4. Configuration issues
5. Communication between browsers and Squid
6. Squid Log Files
7. Operational issues
8. Memory
9. The Cache Manager
10. Access Controls
11. Troubleshooting
12. How does Squid work?
13. Multicast
14. System-Dependent Weirdnesses
15. Redirectors
16. Cache Digests
17. Interception Caching/Proxying
18. SNMP
19. Squid version 2
20. httpd-accelerator mode
21. Related Software
22. DISKD
23. Authentication
24. Terms and Definitions
25. Security Concerns
FAQS
» Advanced Routing & Traffic Control
» General FAQ
» Squid Proxy Server
» Sendmail
» Fetchmail
» Postfix
» Connecting Mobile Phone
» Paging from Linux
» Standard Commands
» Some common terms
Linux HOWTOs
- Single List of HOWTOs
-
Warning: file(link1.inc) [function.file]: failed to open stream: No such file or directory in /home/.showoff/linuxfaqs/linux-faqs.com/link1.php on line 12

Warning: Invalid argument supplied for foreach() in /home/.showoff/linuxfaqs/linux-faqs.com/link1.php on line 16

-
Warning: file(link2.inc) [function.file]: failed to open stream: No such file or directory in /home/.showoff/linuxfaqs/linux-faqs.com/link2.php on line 12

Warning: Invalid argument supplied for foreach() in /home/.showoff/linuxfaqs/linux-faqs.com/link2.php on line 16

-
Warning: file(link3.inc) [function.file]: failed to open stream: No such file or directory in /home/.showoff/linuxfaqs/linux-faqs.com/link3.php on line 12

Warning: Invalid argument supplied for foreach() in /home/.showoff/linuxfaqs/linux-faqs.com/link3.php on line 16

-
Warning: file(link4.inc) [function.file]: failed to open stream: No such file or directory in /home/.showoff/linuxfaqs/linux-faqs.com/link4.php on line 12

Warning: Invalid argument supplied for foreach() in /home/.showoff/linuxfaqs/linux-faqs.com/link4.php on line 16

-
Warning: file(link5.inc) [function.file]: failed to open stream: No such file or directory in /home/.showoff/linuxfaqs/linux-faqs.com/link5.php on line 12

Warning: Invalid argument supplied for foreach() in /home/.showoff/linuxfaqs/linux-faqs.com/link5.php on line 16

-
Warning: file(link6.inc) [function.file]: failed to open stream: No such file or directory in /home/.showoff/linuxfaqs/linux-faqs.com/link6.php on line 12

Warning: Invalid argument supplied for foreach() in /home/.showoff/linuxfaqs/linux-faqs.com/link6.php on line 16

- ISP-Connectivity
- LILO
- META-FAQ
- Linux Miniloader - HOWTO
- Netscape+Proxy
- Querying-libiptc-HOWTO
- Remote-Serial-Console-HOWTO
- Software-RAID-HOWTO
- Tips-HOWTO
- Unix-and-Internet-Fundamentals-HOWTO
- VideoLAN-HOWTO
- WWW-mSQL-HOWTO
- XDM-Xterm
- ADSL Bandwidth Management
- Compile Apache
- Make a Bootdisk
- Linux-Windows9x-Grub
- Linux-Windows
- Linux Crash Recovery
- Optimise Squid
- Block websites in Squid
- Broadcast webcam in linux
- Compile RedHat Linux kernel
- Implement Firewall Security
- Increase Harddrive Performance
- Mount NTFS filesystem
- Patch / rebuild SRPM
- Secure Linux
- Set up a DHCP Server
- Set up an FTP server
- Set up Linux as a Router
- Use Cron
- Samba
Miscellaneous
» All Ports
» Spammers fetch email addresses
» Mounting NTFS in linux
» Linux Gazette
» Linux Man Pages
» Linux Directory
Linux Man Pages
- Section 1
- Section 2
- Section 3
- Section 4
- Section 5
- Section 6
- Section 7
- Section 8
Linux Directory
- General Information
- Linux Hardware
- Software / Applications
- Web Technology
- Software Development
- Linux Distributions
- Linux Publications
- Linux Beginners


 
Next Previous Contents

1. About Squid, this FAQ, and other Squid information resources

1.1 What is Squid?

Squid is a high-performance proxy caching server for web clients, supporting FTP, gopher, and HTTP data objects. Unlike traditional caching software, Squid handles all requests in a single, non-blocking, I/O-driven process.

Squid keeps meta data and especially hot objects cached in RAM, caches DNS lookups, supports non-blocking DNS lookups, and implements negative caching of failed requests.

Squid supports SSL, extensive access controls, and full request logging. By using the lightweight Internet Cache Protocol, Squid caches can be arranged in a hierarchy or mesh for additional bandwidth savings.

Squid consists of a main server program squid, a Domain Name System lookup program dnsserver, some optional programs for rewriting requests and performing authentication, and some management and client tools. When squid starts up, it spawns a configurable number of dnsserver processes, each of which can perform a single, blocking Domain Name System (DNS) lookup. This reduces the amount of time the cache waits for DNS lookups.

Squid is derived from the ARPA-funded Harvest project.

1.2 What is Internet object caching?

Internet object caching is a way to store requested Internet objects (i.e., data available via the HTTP, FTP, and gopher protocols) on a system closer to the requesting site than to the source. Web browsers can then use the local Squid cache as a proxy HTTP server, reducing access time as well as bandwidth consumption.

1.3 Why is it called Squid?

Harris' Lament says, ``All the good ones are taken."

We needed to distinguish this new version from the Harvest cache software. Squid was the code name for initial development, and it stuck.

1.4 What is the latest version of Squid?

Squid is updated often; please see the Squid home page for the most recent versions.

1.5 Who is responsible for Squid?

Squid is the result of efforts by numerous individuals from the Internet community. Duane Wessels of the National Laboratory for Applied Network Research (funded by the National Science Foundation) leads code development. Please see the CONTRIBUTORS file for a list of our excellent contributors.

1.6 Where can I get Squid?

You can download Squid via FTP from the primary FTP site or one of the many worldwide mirror sites.

Many sushi bars also have Squid.

1.7 What Operating Systems does Squid support?

The software is designed to operate on any modern Unix system, and is known to work on at least the following platforms:

  • Linux
  • FreeBSD
  • NetBSD
  • OpenBSD
  • BSDI
  • Mac OS/X
  • OSF/Digital Unix/Tru64
  • IRIX
  • SunOS/Solaris
  • NeXTStep
  • SCO Unix
  • AIX
  • HP-UX
  • OS/2

For more specific information, please see platforms.php. If you encounter any platform-specific problems, please let us know by registering a entry in our bug database.

1.8 Does Squid run on Windows NT?

Recent versions of Squid will compile and run on Windows/NT with the Cygwin / Mingw packages.

Guido Serassio maintains the native NT port of Squid and is actively working on having the needed changes integrated into the standard Squid distribution. Partially based on earlier NT port by Romeo Anghelache.

LogiSense has ported Squid to Windows NT and sells a supported version. You can also download the source from their FTP site. Thanks to LogiSense for making the code available as required by the GPL terms.

1.9 What Squid mailing lists are available?

  • squid-users@squid-cache.org: general discussions about the Squid cache software. Subscribe via squid-users-subscribe@squid-cache.org. Previous messages are available for browsing at the Squid Users Archive, and also at theaimsgroup.com.
  • squid-users-digest: digested (daily) version of above. Subscribe via squid-users-digest-subscribe@squid-cache.org.
  • squid-announce@squid-cache.org: A receive-only list for announcements of new versions. Subscribe via squid-announce-subscribe@squid-cache.org.
  • squid-bugs@squid-cache.org: A closed list for sending us bug reports. Bug reports received here are given priority over those mentioned on squid-users.
  • squid@squid-cache.org: A closed list for sending us feed-back and ideas.
  • squid-faq@squid-cache.org: A closed list for sending us feed-back, updates, and additions to the Squid FAQ.

We also have a few other mailing lists which are not strictly Squid-related.

  • cache-snmp@ircache.net: A public list for discussion of Web Caching and SNMP issues and developments. Eventually we hope to put forth a standard Web Caching MIB.
  • icp-wg@ircache.net: Mostly-idle mailing list for the nonexistent ICP Working Group within the IETF. It may be resurrected some day, you never know!

1.10 I can't figure out how to unsubscribe from your mailing list.

All of our mailing lists have ``-subscribe'' and ``-unsubscribe'' addresses that you must use for subscribe and unsubscribe requests. To unsubscribe from the squid-users list, you send a message to squid-users-unsubscribe@squid-cache.org.

1.11 What other Squid-related documentation is available?

1.12 Does Squid support SSL/HTTPS/TLS?

As of version 2.5, Squid can terminate SSL connections. This is perhaps only useful in a surrogate (http accelerator) configuration. You must run configure with --enable-ssl. See https_port in squid.conf for more information.

Squid also supports these encrypted protocols by ``tunelling'' traffic between clients and servers. In this case, Squid can relay the encrypted bits between a client and a server.

Normally, when your browser comes across an https URL, it does one of two things:

  1. The browser opens an SSL connection directly to the origin server.
  2. The browser tunnels the request through Squid with the CONNECT request method.

The CONNECT method is a way to tunnel any kind of connection through an HTTP proxy. The proxy doesn't understand or interpret the contents. It just passes bytes back and forth between the client and server. For the gory details on tunnelling and the CONNECT method, please see RFC 2817 and Tunneling TCP based protocols through Web proxy servers (expired).

1.13 What's the legal status of Squid?

Squid is copyrighted by the University of California San Diego. Squid uses some code developed by others.

Squid is Free Software.

Squid is licensed under the terms of the GNU General Public License.

1.14 Is Squid year-2000 compliant?

We think so. Squid uses the Unix time format for all internal time representations. Potential problem areas are in printing and parsing other time representations. We have made the following fixes in to address the year 2000:

  • cache.log timestamps use 4-digit years instead of just 2 digits.
  • parse_rfc1123() assumes years less than "70" are after 2000.
  • parse_iso3307_time() checks all four year digits.

Year-2000 fixes were applied to the following Squid versions:

  • squid-2.1: Year parsing bug fixed for dates in the "Wed Jun 9 01:29:59 1993 GMT" format (Richard Kettlewell).
  • squid-1.1.22: Fixed likely year-2000 bug in ftpget's timestamp parsing (Henrik Nordstrom).
  • squid-1.1.20: Misc fixes (Arjan de Vet).

Patches:

Squid-2.2 and earlier versions have a New Year bug. This is not strictly a Year-2000 bug; it would happen on the first day of any year.

1.15 Can I pay someone for Squid support?

Yep. Please see the commercial support page.

1.16 Squid FAQ contributors

The following people have made contributions to this document:

Please send corrections, updates, and comments to: squid-faq@squid-cache.org.

1.17 About This Document

This document is copyrighted (2000) by Duane Wessels.

This document was written in SGML and converted with the SGML-Tools package.

Most current version of this document can always be found at http://www.squid-cache.org/Doc/FAQ/ in HTML, Plain Text, Postscript and SGML formats.

Want to contribute? Please write in SGML...

It is easier for us if you send us text which is close to "correct" SGML. The SQUID FAQ currently uses the LINUXDOC DTD. Its probably easiest to follow examples in the this file. Here are the basics:

Use the <url> tag for links, instead of HTML <A HREF ...>

        <url url="http://www.squid-cache.org" name="Squid Home Page">

Use <em> for emphasis, config options, and pathnames:

        <em>usr/local/squid/etc/squid.conf</em>
        <em/cache_peer/

Here is how you do lists:

        <itemize>
        <item>foo
        <item>bar
        </itemize>

Use <verb>, just like HTML's <PRE> to show unformatted text.


Next Previous Contents
 
Random Linux Commands
RPM
Red Hat Package Manager, which is a system for working with complete software packages. Files usually have a .rpm extension and can be installed using various tools, including KPackage and RPMDrake. The system will alert you if other packages are needed before you can install new software.

Common Linux terms
Linux-FAQs Forum Categories
» About Forum
» Hardware Troubleshooting in Linux
» Linux Entertainment
» Resources
» Software toubleshooting and configuration
All Linux-FAQs Forums
» Crash Recovery
» FAQs
» Forum Talk
» Games
» General
» Linux Audio Support
» Linux Hardware / Driver
» Linux Installation Support
» Linux misc.
» Linux Networking
» Linux Newbies
» Linux Printing Support
» Linux Security
» Linux Video Support
» Mail Server
» Multimedia
» Tutorials
» Web Proxy Server
» Web Server


 
Powered by HTML
Linux-faqs.com Copyright, All rights reserved www.linux-faqs.com. Peeyush Maurya.