Pbr Configuration Guidelines - Cisco Catalyst 3550 series Software Configuration Manual

Chapter 31 Configuring IP Unicast Routing
PBR is applied to incoming packets. All packets received on an interface with PBR enabled are
considered for PBR. The switch passes the packets through route maps. Based on the criteria defined in
the route maps, packets are forwarded (routed) to the appropriate next hop. For more information about
configuring route maps see the
page
For details about PBR commands and keywords, refer to the Cisco IOS IP and IP Routing Command
Note
Reference for Release 12.1. For a list of PBR commands not supported by the switch, see
"Unsupported CLI Commands in Cisco IOS Release 12.1(19)EA1."

PBR Configuration Guidelines

Before configuring PBR, you should be aware of this information:
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To use PBR, you must have the EMI installed on your switch.
Multicast traffic is not policy-routed. PBR applies to only to unicast traffic.
You can enable PBR on a routed port, an SVI, or an EtherChannel port channel in Layer 3 mode.
You can define a maximum of 247 IP policy route-maps on the switch.
VRF and PBR are mutually-exclusive on a switch interface. You cannot enable VRF when PBR is
enabled on an interface. In contrast, you cannot enable PBR when VRF is enabled on an interface.
WCCP and PBR are mutually-exclusive on a switch interface. You cannot enable WCCP when PBR
is enabled on an interface. In contrast, you cannot enable PBR when WCCP is enabled on an
interface.
The number of TCAM entries used by PBR depends on the route-map itself, the ACLs used, and the
order of the ACLs and route-map entries.
You must modify the SDM template to enable the switch to support the 144-bit Layer 3 TCAM. Use
the sdm prefer extended-match, sdm prefer access extended-match, or the sdm prefer routing
extended-match global configuration commands to reformat the TCAM space allocated to unicast
routing in the default, access, or routing template, respectively. Reformatting the unicast routing
TCAM reduces by half the number of supported unicast routes in the template.
See the "Optimizing System Resources for User-Selected Features" section on page 7-27
"Displaying ACL Resource Usage and Configuration Problems" section on page 28-43
information about managing the memory resources in the switch.
"Using Route Maps to Redistribute Routing Information" section on
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring Protocol-Independent Features
Appendix C,
and the
for more
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