Riverstone Networks WICT1-12 - Manual (Page 518)

22-20 Riverstone Networks RS Switch Router User Guide Release 8.0
Web Caching Web Hosting Configuration
In the preceding example, a bypass list for testweb1 is created. The list has an address range of 135.142.179.14 to
135.142.179.21. HTTP requests for these sites will not be redirected
Proxy Server Redundancy
Some networks use proxy servers that receive HTTP requests on a non-standard port number (i.e., not port 80). When
the proxy server is available, all HTTP requests are handled by the proxy server. The RS can provide proxy server
redundancy by transparently redirecting HTTP connections to the cache servers should the proxy server fail. To
achieve this, the RS must be configured to redirect HTTP requests on the (non-standard) HTTP port used by the proxy
server.
In the following example, the HTTP port number for testweb1 is set to port 40:
Disabling Redirection on an Inbound Interface or Port
When you apply a caching policy, HTTP requests that are received on all inbound interfaces on the RS are redirected
to the local cache servers. You can specify that redirection of requests not be done for a particular inbound interface or
port.
In the following example, HTTP requests on the interface int100 will not be redirected:
Specifying Protocol for Redirected Traffic
By default, only TCP traffic is redirected to the local cache servers. You can specify a different IP protocol for the
traffic that is to be redirected. For example, you can specify that UDP traffic be redirected. For any protocol other than
TCP or UDP, you will need to specify the assigned IP protocol number as defined in RFC 1060.
The following example specifies that UDP traffic will be redirected:
Configuring the traffic to be redirected (with the
web-cache set redirect-protocol
command) and the HTTP
port (with the
web-cache set http-port
command) allows transparent redirection of traffic for any application
that is supported by the cache servers.
Distributing Frequently-Accessed Sites Across Cache Servers
The RS uses the destination IP address of the HTTP request to determine to which cache server to send the request.
However, if there is a Web site that is being accessed very frequently, the cache server serving requests for this
destination address may become overloaded with user requests. You can specify one of the following policies for
distributing certain destination addresses across the cache servers:
• round-robin, where the RS selects the cache server on a rotating basis regardless of the load on
individual servers
rs(config)# web-cache testweb1 set http-port 40
rs(config)# web-cache testweb1 create filter interface int100
rs(config)# web-cache testweb1 set redirect protocol udp