Cisco Catalyst 2960 Series, Configuration Manual

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Restrictions for NetFlow Lite
The following are restrictions for NetFlow Lite:
• Flow Record restrictions:
When a flow monitor has collect interface output as the collect field in the flow record, the field will
return a value of NULL when a flow gets created for any of the following addresses:
• L3 broadcast
• L2 broadcast
• L3 Multicast
• L2 Multicast
• L2 unknown destination.
• Monitor restrictions:
◦ Monitor attachment is only supported in the ingress direction.
◦ One monitor per interface is supported, although multiple exporters per interface are supported.
◦ Only permanent and normal cache is supported for the monitor; immediate cache is not supported.
◦ Changing any monitor parameter will not be supported when it is applied on any of the interfaces
or VLANs.
◦ When both the port and VLANs have monitors attached, then VLAN monitor will overwrite the
port monitor for traffic coming on the port.
◦ Flow monitor type and traffic type (type means IPv4, IPv6, and data link) should be same for the
flows to be created.
◦ You cannot attach an IP and port-based monitor to an interface at the same time on the switch. A
48-port switch supports a maximum of 48 monitors (IP or port-based) and for 256 SVIs, you can
configure up to 256 monitors (IP or port-based).
◦ When running the show flow monitor flow_name cache command, the switch displays cache
information from an earlier switch software version (Catalyst 2960-S) with all fields entered as
zero. Ignore these fields, as they are inapplicable to the switch.
• Sampler restrictions:
◦ Only sampled NetFlow is supported.
◦ For both port and VLANS, a total of only 4 samplers (random or deterministic) are supported on
the switch.
◦ The sampling minimum rate for both modes is 1 out of 32 flows, and the sampling maximum rate
for both modes is 1 out of 1022 flows.
◦ You must associate a sampler with a monitor while attaching it to an interface. Otherwise, the
command will be rejected. Use the
ip flow monitor monitor_name sampler s ampler_name input
interface configuration command to perform this task.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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Restrictions for NetFlow Lite