• Up to eight service groups are supported at the same time on the same client interface. • The Layer 2 rewrite forwarding method is supported; but generic routing encapsulation (GRE) is not. • Direct Layer 2 connectivity to content engines is required when Layer 2 mode is deployed; Layer 3 connectivity of one or more hops away is not supported. • Ternary content addressable memory (TCAM) friendly mask-based assignment is supported, but the hash bucket-based method is not. • When the TCAM space is exhausted, traffic is not redirected but is forwarded normally. • The WCCP version 2 standard allows for support of up to 256 distinct masks.
However, a Cisco Catalyst 9000 series switch supports only mask assignment tables with a single mask. • A content engine configured for mask assignment that tries to join a farm where the selected assignment method is hash remains out of the farm as long as the cache engine assignment method does not match that of the existing farm. • WCCP redirection is not supported on Multiprotocol Label Switching (MPLS) and port-channel interfaces. • WCCP high availability is not supported in modular, stacking, and StackWise Virtual (SVL) mode. • The packets redirected counter in the output of the command show ip wccp detail only increments whenever a packet is redirected via CPU switching.
Whenever Cisco Express Forwarding (CEF) is being used with inbound WCCP redirection, L2 forwarding method, and mask assignment, all WCCP traffic should be redirected via hardware. When traffic is redirected via hardware the counters will not increment. Catalyst 9000 Series Switches Access Control Lists When WCCP is using the mask assignment, any redirect list is merged with the mask information from the appliance and the resulting merged ACL is passed down to the Catalyst 9000 series switch hardware. Only Permit or Deny ACL entries from the redirect list in which the protocol is IP or exactly matches the service group protocol are merged with the mask information from the appliance.
The following restrictions apply to the redirect-list ACL: • The ACL must be an IPv4 extended ACL. • Only individual source or destination port numbers may be specified; port ranges cannot be specified. • The only valid matching criteria in addition to individual source or destination port numbers are dscp or tos . • The use of fragments , time-range , or options keywords, or any TCP flags is not permitted. • If the redirect ACL does not meet the restrictions shown, the system will log the following error message: WCCP-3-BADACE: Service group>, invalid access-list entry (seq: , reason: ) Configuring WCCP Restrictions for WCCP Configuring WCCP 2