Chapter 23: Transparent Web Cache Balancing Configuration; Understanding Transparent Web Cache Balancing (Twcb) - Enterasys Matrix DFE-Gold Series Configuration Manual

Transparent Web Cache Balancing Configuration
This chapter describes the Transparent Web Cache Balancing (TWCB) commands and how to use
them.

Understanding Transparent Web Cache Balancing (TWCB)

Transparent Web Cache Balancing (TWCB) provides for the storing of frequently accessed web
objects on a cache of local servers. Each HTTP request is transparently redirected by the N‐Series
router to a configured cache server. When a user first accesses a web object that object is stored on
a cache server. Each subsequent request for the object uses this cached object. Web caching allows
multiple users to access web objects stored on local cache servers with a much faster response time
than accessing the same objects over an internet connection or through a default gateway. This can
also result in substantial cost savings by reducing the internet bandwidth usage.
The N‐Series router does not act as a cache for web objects; rather, it redirects HTTP requests to
local servers on which web objects are cached. The cache servers should have a web‐based proxy
cache running. The Squid application is an example of a web‐based proxy cache.
Implementing a TWCB configuration requires users to configure a routed network with IP
interfaces that allow the N‐Series router to send requests for the internet to the correct web
caching device.
There are five aspects to TWCB configuration:
• Create the server farms that will cache the web objects. A server farm is made up of 1 or more
cache servers.
• Specify the end users whose HTTP requests will or will not be redirected to the cache servers.
This step is optional. If no hosts are configured, the firmware redirects all HTTP requests.
• Specify the web site hosts that will not take part in TWCB.
• Create a web‐cache that the server farms will be associated with.
• Apply the caching policy to an outbound interface to redirect HTTP traffic on that interface to
the cache servers.
Figure 23‐1 provides an example of a TWCB configuration overview. The web‐cache is made up of
server farms which logically group one or more cache servers. In our example, Cache1 is the name
of the web‐cache. It is made up of two server farms: s2Servers and s1Servers. The s1Server server
Router: Unless otherwise specified, the commands covered in this chapter can be executed only
when the device is in router mode. For details on how to enable router configuration modes, refer to
Enabling Router Configuration Modes on page
Note: An Enterasys Feature Guide document that contains a complete discussion on TWCB
configuration exists at the following Enterasys web site:
manuals/
2-103.
http://www.enterasys.com/support/
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