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Catalyst 3750 Switch Software Configuration Guide
OL-8550-09
Chapter 38 Configuring IP Unicast Routing
Configuring Protocol-Independent Features
For more information about configuring route maps, see the “Using Route Maps to Redistribute Routing
Information” section on page 38-94.
You can use standard IP ACLs to specify match criteria for a source address or extended IP ACLs to
specify match criteria based on an application, a protocol type, or an end station. The process proceeds
through the route map until a match is found. If no match is found, normal destination-based routing
occurs. There is an implicit deny at the end of the list of match statements.
If match clauses are satisfied, you can use a set clause to specify the IP addresses identifying the next
hop router in the path.
For details about PBR commands and keywords, see the Cisco IOS IP Command Reference, Volume 2 of
3: Routing Protocols, Release 12.2. For a list of PBR commands that are visible but not supported by the
switch, see Appendix D, “Unsupported Commands in Cisco IOS Release 12.2(55)SE,”
PBR configuration is applied to the whole stack, and all switches use the stack master configuration.
Note This software release does not support PBR when processing IPv4 and IPv6 traffic.
PBR Configuration Guidelines
Before configuring PBR, you should be aware of this information:
• To use PBR, you must have the IP services image installed on the stack master.
• Multicast traffic is not policy-routed. PBR applies to only to unicast traffic.
• You can enable PBR on a routed port or an SVI.
• The switch does not support route-map deny statements for PBR.
• You can apply a policy route map to an EtherChannel port channel in Layer 3 mode, but you cannot
apply a policy route map to a physical interface that is a member of the EtherChannel. If you try to
do so, the command is rejected. When a policy route map is applied to a physical interface, that
interface cannot become a member of an EtherChannel.
• You can define a maximum of 246 IP policy route maps on the switch stack.
• You can define a maximum of 512 access control entries (ACEs) for PBR on the switch stack.
• When configuring match criteria in a route map, follow these guidelines:
–
Do not match ACLs that permit packets destined for a local address. PBR would forward these
packets, which could cause ping or Telnet failure or route protocol flapping.
–
Do not match ACLs with deny ACEs. Packets that match a deny ACE are sent to the CPU, which
could cause high CPU utilization.
• To use PBR, you must first enable the routing template by using the sdm prefer routing global
configuration command. PBR is not supported with the VLAN or default template. For more
information on the SDM templates, see Chapter 8, “Configuring SDM Templates.”
• VRF and PBR are mutually exclusive on a switch interface. You cannot enable VRF when PBR is
enabled on an interface. The reverse is also true, you cannot enable PBR when VRF is enabled on
an interface.
• Web Cache Communication Protocol (WCCP) and PBR are mutually exclusive on a switch
interface. You cannot enable WCCP when PBR is enabled on an interface. The reverse is also true,
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.