Network Router User Manual

Chapter 17: Web Hosting Configuration Guide
244 SmartSwitch Router User Reference Manual
Web Caching
Web caching provides a way to store frequently accessed Web objects on a cache of local
servers. Each HTTP request is transparently redirected by the SSR 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 servers with a much faster response time than
accessing the same objects over a WAN connection. This can also result in substantial cost
savings by reducing the WAN bandwidth usage.
Note:
The SSR itself does not act as cache for web objects. It redirects HTTP requests to
local servers on which the web objects are cached. One or more local servers are
needed to work as cache servers with the SSR’s web caching function.
Configuring Web Caching
The following are the steps in configuring Web caching on the SSR:
1. Create the cache group (a list of cache servers) to cache Web objects.
2. Specify the hosts whose HTTP requests will be redirected to the cache servers. This
step is optional; if you do not explicitly define these hosts, then all HTTP requests are
redirected.
3. Apply the caching policy to an outbound interface to redirect HTTP traffic on that
interface to the cache servers.
Creating the Cache Group
You can specify either a range of contiguous IP addresses or a list of up to four IP
addresses to define the servers when the cache group is created. If you specify multiple
servers, load balancing is based on the destination address of the request. If any cache
server fails, traffic is redirected to the other active servers.
To create the cache group, enter the following command in Configure mode:
Note:
If a range of IP addresses is specified, the range must be contiguous and contain
no more than 256 IP addresses.
Create the cache group.
web-cache <cache-name> create server-list
<server-list-name> range <ipaddr-
range>
|list <ipaddr-list>