Cisco ASR 1000 Series Configuration Manual page 59

Configuring WCCP
Layer 2 Forwarding and Return
The following limitations apply to WCCP Layer 2 Forwarding and Return:
• Layer 2 redirection requires that content engines be directly connected to an interface on each WCCP
router. Unless multicast IP addresses are used, WCCP configuration of the content engine must reference
the directly connected interface IP address of the WCCP router and not a loopback IP address or any
other IP address configured on the WCCP router.
Cisco Catalyst 4500 Series Switches
The following limitations apply to Cisco Catalyst 4500 series switches:
• Catalyst 4500 series switches do not support WCCPv1.
• Up to eight service groups are supported at the same time on the same client interface.
• The Layer 2 (L2) rewrite forwarding method is supported, but generic routing encapsulation (GRE) is
not.
• Direct L2 connectivity to content engines is required; Layer 3 (L3) 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.
• Redirect ACL for WCCP on a client interface is not supported.
• Incoming traffic redirection on an interface is supported, but outgoing traffic redirection is not.
• When TCAM space is exhausted, traffic is not redirected; it is forwarded normally.
• The WCCP version 2 standard allows for support of up to 256 distinct masks. However, a Catalyst 4500
series switch supports only mask assignment tables with a single mask.
Cisco Catalyst 6500 Series Switches
The following limitation apply to Cisco Catalyst 6500 series switches:
• With a Policy Feature Card 2 (PFC2), Cisco IOS Release 12.2(17d)SXB and later releases support
WCCP.
• With a PFC3, Cisco IOS Release 12.2(18)SXD1 and later releases support WCCP.
• With a PFC4, Cisco IOS Release 12.2(50)SY and later releases support WCCP and introduce support
for WCCP GRE decapsulation, WCCP mask assignment, and WCCP exclude capability in hardware.
• To use the WCCP Layer 2 PFC redirection feature, configure WCCP on the Catalyst 6500 series switch
and configure accelerated WCCP on the cache engine as described in the
• Cisco Application and Content Networking System (ACNS) software releases later than Release 4.2.2
support WCCP Layer 2 Policy Feature Card (PFC) redirection hardware acceleration.
• 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.
• When WCCP Layer 2 PFC redirection is the forwarding method for a service group, the packet counters
in the show ip wccp service-number command output display flow counts instead of packet counts.
IP Application Services Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 1000)
Restrictions for WCCP
Transparent Caching document.
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