Figure 5 illustrates policy-based routing for HTTP objects. This routing scheme has the following characteristics:
✔All client Internet traffic is sent to a router that feeds the appliance.
✔The router sends port 80 (HTTP) traffic to the appliance and sends the remaining traffic to the next hop router.
✔The ARM translates intercepted requests into appliance requests so they can be served.
✔Translated requests are sent to the appliance.
✔Web documents to be served transparently are readdressed by the ARM on the return path to the client, so that the documents appear to have come straight from the origin server.
An appliance cluster with virtual IP failover adds reliability; if one node fails, another node can take up its transparency requests. See Virtual IP failover‚ on page 146.
world wide web
end users | router |
| non80 |
all | non port:80 traffic |
80port:80 traffic
Intel NetStructure Cache Appliance
Figure 5 Using a router to filter HTTP requests
ARM redirection
The ARM can make two changes to an incoming packet’s address: its destination IP address and its destination port.
✔Typically, HTTP packet destination IPs and ports are readdressed with the IP address of the Intel NetStructure Cache Appliance and the appliance’s HTTP proxy port (usually port 8080).
Appendix A Caching Solutions and Performance | 125 |
