A
proxy server can be used to store (or "cache")
frequently visited web sites.
This can be an advantage
on a school network, where multiple students on the network visit
the same site. The first student to visit a web site makes a connection,
via the proxy server, to the desired web site on the Internet.
The proxy server "remembers" the
web site, so that when the next student on the network visits the
same site, the page loads from the local proxy server, across
the local network, rather than competing with traffic directly
on the Internet.
In this way a proxy server
can significantly improve perceived Internet access speed for users
on the network. However, "live" sites, such as web based e-mail
sites and search sites, cannot be cached, for obvious reasons. Web sites with server side
scripts, or links to advertising content servers, may also frustrate
the use of a proxy cache.
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 While the stored
content will load from the local proxy, the scripts or advertisements
will still need an external connection.
Still, despite this issue,
the general network speed for Internet access in a school should
still be improved with the use of a caching proxy server.
A proxy server can also be
used to filter access to web pages.
Many school systems use a central
proxy server, which services all schools within the system.
Proxy servers installed in
individual schools must connect to the internet through the organisation's central proxy server. Having
one proxy (at the school) connecting to the Internet via another
proxy server (at the organisation's head office) is known as cascading proxy
servers.
The organisation's proxy server in this
setup is referred to as the parent proxy.
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You can setup
a local caching proxy server running on a computer using either Linux, Macintosh or Windows operating systems, regardless of
the platform of the computers on your network.
Macintosh computers can connect
to the Internet via a Windows or Linux proxy, and visa versa,
due to the platform independent TCP/IP network
protocol.
There are a number of proxy
servers available which are suitable for use in schools.
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Commercially available
proxy servers include Sentral, Wingate (Win)
and Vicom (Mac
and Win). Windows server also
includes a proxy server (free for site-licensed schools.) The most widely used proxy
server (by a long margin) is Squid.
Squid is
the Unix-based proxy server used by many ISPs and is something of an "industry standard".
Squid is
very reliable, fast and efficient, and is free. Once up and
running a Squid/Linux machine can run for years without
problems. |
- SENTRAL
- A commercial
product which includes the Squid proxy server, as well as a variety of other useful modules for schools. The neat Sentral web interface, clear documentation and on-line support makes
the use of this server a breeze for even the most inexperienced
user.
Hardware: Late model PC, with suitable RAM and HDD space.
Cost: around $AU900.
SquidMan- A Mac OS
X implementation of Squid with an easy installation and setup
interface.
Hardware: Any recent Mac.
Cost: Free
Linux / Squid - If you need a proxy server, and like to have a tinker....
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install your favourite Linux distro,
-
install Squid;
- install WebMin (to
get a web interface to administer Squid).
A bit of fiddling, but fast and reliable even on older hardware.
If you need some installation info, do some googling of Squid and your flavour of Linux.
Hardware: Pentium III +
Configure network computers' preferences to use the IP address and port number
(3128) of the proxy server running Squid.
If you are also using the DansGuardian filter on the proxy server, the port
number is 8080
Cost: Free
WebMin- Provides a web interface to start/stop
and administer Squid in a Linux environment. Download the installer package for your favorite flavour of Linux.
Cost: Free
This is a utility that requires Squid to already be running on the host server.
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- Proxy
Switcher (Win)
- Client utility. Handy for Win laptops - switch
between school proxy and home settings with one click. Lite
version is free.
(Mac users can do the same thing with Location manager).
WebMin (Linux/Mac
OS X)- Provides
a web interface for Linux-based software (such as Squid, Dansguardian,
etc) installed in OSX or Linux. See also:
WebMin
OSX Package
OSX installation
info at the WebMin site.
Authoxy (Mac)- A utility for interpreting and forwarding pac file requests at a system
level.
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