Chapter 25 Configuring Rmon; Understanding How Rmon Works - Cisco WS-C2950SX-48-SI Configuration Manual

Configuring RMON
This chapter describes how to configure RMON on the Catalyst enterprise LAN switches.
For complete syntax and usage information for the commands used in this chapter, refer to the
Note
Catalyst 4500 Series, Catalyst 2948G, and Catalyst 2980G Switches Command Reference.
This chapter consists of these sections:
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Understanding How RMON Works

RMON is an Internet Engineering Task Force (IETF) standard monitoring specification that allows
various network agents and console systems to exchange network monitoring data. The supervisor
engine software provides embedded support for these components of the RMON specification (see the
"Supported RMON and RMON2 MIB Objects" section on page 25-2
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The embedded RMON agent allows the switch to monitor network traffic from all ports simultaneously
at the data-link layer of the OSI model without requiring a dedicated monitoring probe or network
analyzer.
78-15486-01
Understanding How RMON Works, page 25-1
Enabling RMON, page 25-2
Viewing RMON Data, page 25-2
Supported RMON and RMON2 MIB Objects, page 25-2
The following RMON groups are defined in RFC 1757:
– Statistics (RMON group 1) for Ethernet, Fast Ethernet, Fast EtherChannel, and Gigabit Ethernet
switch ports (uses 140 bytes of supervisor engine module RAM per port)
– History (RMON group 2) for Ethernet, Fast Ethernet, Fast EtherChannel, and Gigabit Ethernet
switch ports (uses 3 KB of supervisor engine module RAM for the first 50 buckets; each
additional bucket uses another 56 bytes)
– Alarm (RMON group 3; each alarm configured uses 1.3 KB of supervisor engine RAM)
Event (RMON group 9; each event configured uses 1.3 KB of supervisor engine RAM)
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The following RMON2 groups are defined in RFC 2021:
UsrHistory (RMON2 group 18)
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ProbeConfig (RMON2 group 19)
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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide
C H A P T E R
for details):
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