The Web Cache Communication Protocol (WCCP) is a Cisco-developed content-routing technology that intercepts IP packets and redirects those packets to a destination other than that specified in the IP packet.
UDP port 2048
Redirecting or returning traffic via GRE (client to be multiple hops away from server) or L2 Forwarding (client and server on the same subnet)
Device
Function
WCCP Client
Content Engine/Proxy
A device, such as a Secure Web Appliance (SWA) that receives redirected traffic to either fulfill the request from its local cache or process it further.
WCCP Server
Router/Switch
A WCCP-enabled router or L3 switch that intercepts and redirects traffic based on specified service groups.
Service Group
Configuration
A logical grouping of WCCP servers and clients that share the same configuration settings for traffic redirection.
Configuring WCCP on Routers
Type
Function
What it controls
Example Devices/Apps
group-list
ACL
Clients Filter
Defines which Cache Engines (clients) are allowed to join the service group.
SWA with IP 10.0.0.10
redirect-list
ACL
Traffic Selection
An ACL that identifies specific user traffic (e.g., HTTP/HTTPS) to be redirected.
HTTP (Port 80), HTTPS (Port 443)
ip wccp web-cache|<NUMBER>
Identifier
Service Group Defination
web-cache is system pre-defined (service 0) whiled <NUMBER> is custom dynamic-defined (service 51-255).
ip wccp we-cache, ip wccp 80 group-list SWA redirect-list 10