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Catalyst 3750 SwitchSoftware Configuration Guide
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Chapter45 Configuring Cache Services By Using WCCP
Configuring WCCP
WCCP Configuration Guidelines
Before configuring WCCP on your switch, make sure to follow these configuration guidelines:
•The application engines and switches in the same service group must be in the same subnetwork
directly connected to the switch that has WCCP enabled.
•Configure the switch interfaces that are connected to the clients, the application engines, and the
server as Layer 3 interfaces (routed ports and switch virtual interfaces [SVIs]). For WCCP packet
redirection to work, the servers, application engines, and clients must be on different subnets.
•Use only nonreserved multicast addresses when configuring a single multicast address for each
application engine.
•WCCP entries and PBR entries use the same TCAM region. WCCP is supported only on the
templates that support PBR: access, routing, and dual IPv4/v6 routing.
•When TCAM entries are not available to add WCCP entries, packets are not redirected and are
forwarded by using the standard routing tables.
•The number of available policy-based routing (PBR) labels are reduced as more interfaces are
enabled for WCCP ingress redirection. For every interface that supports service groups, one label is
consumed. The WCCP labels are taken from the PBR labels. You need to monitor and manage the
labels that are available between PBR and WCCP. When labels are not available, the switch cannot
add service groups. However, if another interface has the same sequence of service groups, a new
label is not needed, and the group can be added to the interface.
•The routing maximum transmission unit (MTU) size configured on the stack member switches
should be larger than the client MTU size. The MAC-layer MTU size configured on ports connected
to application engines should take into account the GRE tunnel header bytes.
•You cannot configure WCCP and VPN routing/forwarding (VRF) on the same switch interface.
•You cannot configure WCCP and PBR on the same switch interface.
•You cannot configure WCCP and a private VLAN (PVLAN) on the same switch interface.
Enabling the Cache Service
For WCCP packet redirection to operate, you must configure the switch interface connected to the client
to redirect inbound packets.
This procedure shows how to configure these features on routed ports. To configure these features on
SVIs, see the configuration examples that follow the procedure.
Note Before configuring WCCP commands, configure the SDM template, and reboot the switch. For more
information, see Chapter8, “Configuring SDM Templates.”