Configuring RMON

This chapter describes how to configure RMON on the Catalyst 6000 family switches.

Note For complete syntax and usage information for the commands used in this chapter, refer to the Catalyst 6000 Family Command Reference publication.

This chapter consists of these sections:

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 for details):

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 RAM per port)
- History (RMON group 2) for Ethernet, Fast Ethernet, Fast EtherChannel, and Gigabit Ethernet switch ports (uses 3 KB of supervisor engine 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)
The following RMON2 groups are defined in RFC 2021:
- UsrHistory (RMON2 group 18)
- ProbeConfig (RMON2 group 19)

The embedded RMON agent allows the switch to monitor network traffic from all ports simultaneously at Layer 2 without requiring a dedicated monitoring probe or network analyzer.

Enabling RMON

Note RMON is disabled by default.

To enable RMON, perform this task in privileged mode:

Task Command

Step 1

Enable RMON on the switch.

set snmp rmon enable

Step 2

Verify that RMON is enabled.

show snmp

	Task	Command
Step 1	Enable RMON on the switch.	set snmp rmon enable
Step 2	Verify that RMON is enabled.	show snmp

This example shows how to enable RMON on the switch and how to verify that RMON is enabled:

Console> (enable) set snmp rmon enable
SNMP RMON support enabled.
Console> (enable) show snmp
RMON:                       Enabled
Extended RMON:              Extended RMON module is not present
Traps Enabled: 
Port,Module,Chassis,Bridge,Repeater,Vtp,Auth,ippermit,Vmps,config,entity,stpx
Port Traps Enabled: 1/1-2,4/1-48,5/1
Community-Access     Community-String    
----------------     --------------------
read-only            Everyone
read-write           Administrators
read-write-all       Root
Trap-Rec-Address                           Trap-Rec-Community
----------------------------------------   --------------------
172.16.10.10                               read-write
172.16.10.20                               read-write-all
Console> (enable)

Viewing RMON Data

Access to RMON data is available only on a network management system (NMS) that supports RFC 1757 and RFC 2021 (see the "Using CiscoWorks2000" section). You cannot access RMON data through the switch CLI; however, CLI show commands provide similar information (refer to the Catalyst 6000 Family Command Reference publication).

Supported RMON and RMON2 MIB Objects

Table 31-1 lists the RMON and RMON2 MIB objects supported by the supervisor engine software.

Table 31-1: Supervisor Engine RMON and RMON2 Support

Object Identifier (OID) and Description Source

...mib-2(1).rmon(16).statistics(1).etherStatsTable(1)

RFC 1757 (RMON-MIB)

Counters for packets, octets, broadcasts, errors, etc.

...mib-2(1).rmon(16).history(2).historyControlTable(1)
...mib-2(1).rmon(16).history(2).etherHistoryTable(2)

RFC 1757 (RMON-MIB)
RFC 1757 (RMON-MIB)

Periodically samples and saves statistics group counters for later retrieval.

...mib-2(1).rmon(16).alarm(3)

RFC 1757 (RMON-MIB)

A threshold that can be set on critical RMON variables for network management.

...mib-2(1).rmon(16).event(9)

RFC 1757 (RMON-MIB)

Generates SNMP traps when an Alarms group threshold is exceeded and logs the events.

...mib-2(1).rmon(16).usrHistory(18)

RFC 2021 (RMON2-MIB)

Extends history beyond RMON1 link-layer statistics to include any RMON, RMON2, MIB-I, or MIB-II statistic.

...mib-2(1).rmon(16).probeConfig(19)

RFC 2021 (RMON2-MIB)

Displays a list of agent capabilities and configurations.

Object Identifier (OID) and Description	Source
...mib-2(1).rmon(16).statistics(1).etherStatsTable(1)	RFC 1757 (RMON-MIB)
Counters for packets, octets, broadcasts, errors, etc.
...mib-2(1).rmon(16).history(2).historyControlTable(1) ...mib-2(1).rmon(16).history(2).etherHistoryTable(2)	RFC 1757 (RMON-MIB) RFC 1757 (RMON-MIB)
Periodically samples and saves statistics group counters for later retrieval.
...mib-2(1).rmon(16).alarm(3)	RFC 1757 (RMON-MIB)
A threshold that can be set on critical RMON variables for network management.
...mib-2(1).rmon(16).event(9)	RFC 1757 (RMON-MIB)
Generates SNMP traps when an Alarms group threshold is exceeded and logs the events.
...mib-2(1).rmon(16).usrHistory(18)	RFC 2021 (RMON2-MIB)
Extends history beyond RMON1 link-layer statistics to include any RMON, RMON2, MIB-I, or MIB-II statistic.
...mib-2(1).rmon(16).probeConfig(19)	RFC 2021 (RMON2-MIB)
Displays a list of agent capabilities and configurations.

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