Cisco Catalyst 2960 Series, Configuration Manual

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◦ When you attach a monitor using a deterministic sampler, every attachment with the same sampler
uses one new free sampler from the switch (hardware) out of 4 available samplers. You are not
allowed to attach a monitor with any sampler, beyond 4 attachments.
When you attach a monitor using a random sampler, only the first attachment uses a new sampler
from the switch (hardware). The remainder of all of the attachments using the same sampler, share
the same sampler.
Because of this behavior, when using a deterministic sampler, you can always make sure that the
correct number of flows are sampled by comparing the sampling rate and what the switch sends.
If the same random sampler is used with multiple interfaces, flows from any interface can always
be sampled, and flows from other interfaces can always be skipped.
• Stacking Restrictions:
◦ The switch supports homogeneous stacking and mixed stacking. Mixed stacking is supported only
with the Catalyst 2960-S switches. A homogenous stack can have up to eight stack members, while
a mixed stack can have up to four stack members. All switches in a switch stack must be running
the LAN Base image.
◦ The switch supports NetFlow Lite running on a mixed stack configuration, where both Catalyst
2960-X and Catalyst 2960-S switches reside in the same stack. But in such a mixed stack
configuration, the master switch must always be a Catalyst 2960-X switch. The Catalyst 2960-S
switch must never be the master switch in this type of mixed stack configuration.
◦ Each switch in a stack (hardware) can support the creation of a maximum of 16,000 flows at any
time. But as the flows are periodically pushed to the software cache, the software cache can hold
a much larger amount of flows (1048 Kb flows). From the hardware flow cache, every 20 seconds
(termed as poll timer), 200 flows (termed as poll entries) are pushed to software.
◦ Use the
remote command all show platform hulc-fnf poll
command to report on each
switch's current NetFlow polling parameters.
◦ Use the
show platform hulc-fnf poll
command to report on the master switch's current
NetFlow polling parameters.
• Network flows and statistics are collected at the line rate.
• ACL-based NetFlow is not supported.
• Only NetFlow Version 9 is supported for Flexible NetFlow exporter using the export-protocol command
option. If you configure NetFlow Version 5, this version will be accepted, but the NetFlow Version 5
export functionality is neither currently available nor supported.
• The switch supports homogeneous stacking, but does not support mixed stacking.
Information About NetFlow Lite
NetFlow Lite Overview
NetFlow Lite uses flows to provide statistics for accounting, network monitoring, and network planning.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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Information About NetFlow Lite