The Web Cache

The web cache is a logical entity in which server farms are added and rules are configured that govern what TCP data flows should be redirected. Multiple web caches can be configured on a device. Use the show router limit command to determine the number of web caches supported on the device. A web cache supports a single protocol port such as port 80, 443 or 8080. A web cache can be configured per protocol port for each VRF segment configured on the device.

You create a web cache by naming it in router configuration command mode. Once entered, you are placed in TWCB web cache configuration command mode. Once in TWCB web cache configuration command mode, you can:

• Add up to 10 server farms to a web cache.
• Optionally specify a non-standard port for the redirection of HTTP requests. Outbound HTTP requests are directed to port 80 by default.
• Create bypass lists containing a range of host web sites for which HTTP requests are not redirected to the cache servers for this web cache.
• Specify the clients (source IP addresses) whose HTTP requests are or are not redirected to the cache server. Clients permitted redirection take part in TWCB. Clients denied redirection do not take part in TWCB. All clients are permitted redirection by default.
• Configure TWCB source and destination NAT allowing the TWCB router, user clients, and webcache to be located anywhere in the network.