Table of Contents

Overview of Switch Monitoring
Monitoring Switch Ports with Mini-RMON

Using Embedded Mini-RMON

Using VLAN Monitor

Starting VLAN Monitor (SwitchProbe Devices Only)
Understanding VLAN Monitor Displays

Monitoring Switches

The TrafficDirector application uses mini-RMON to continuously monitor all switch ports, and it uses roving RMON to provide additional RMON and RMON2 groups to a selected port when needed. A single SwitchProbe device or Network Analysis Module can provide complete monitoring and analysis of all ports on a selected switch.

The following sections describe the tasks you use to monitor switches:

• Overview of Switch Monitoring

• Monitoring Switch Ports with Mini-RMON

• Using VLAN Monitor

Overview of Switch Monitoring

The TrafficDirector application let you monitor critical interswitch links using dedicated high-speed probing devices such as the Cisco SwitchProbe and Network Analysis Module devices.

You can connect high-speed media agents (Fast Ethernet and FDDI SwitchProbe devices) directly to switch trunk and server ports to provide full, proactive RMON monitoring of the high traffic volume on these critical links.

The TrafficDirector application aggregates the data from mini-RMON, roving RMON agent, and any dedicated SwitchProbe devices you have defined into a consolidated monitoring and diagnostic environment supporting switch and virtual LAN (VLAN) traffic.

A switch is similar to an agent group in several ways because the TrafficDirector application treats each port as an agent; you can monitor each switch port as you would any other SwitchProbe device interface.

For example, you can install domains on ports, set multiple alarms on specific ports, and use the Scope application on switch port displays. You can also start other TrafficDirector applications for a more detailed analysis of traffic on a selected switch port.

Monitoring Switch Ports with Mini-RMON

The TrafficDirector application uses mini-RMON to continuously monitor all ports on a switch. Mini-RMON consists of the RMON domain with only statistics, history, events, and alarms enabled. This provides the TrafficDirector application with enough information to identify a problem. You can then rove the suspect switch port to the analyzer port for more detailed analysis.

Mini-RMON allows the TrafficDirector application to view each switch port as an RMON agent. This feature is especially important in working with microsegmented switched LANs.

• Using Embedded Mini-RMON

Using Embedded Mini-RMON

Mini-RMON embeds only the essential RMON groups (statistics, history, events, and alarms) on each switch port and ignores groups with high resource requirements. When monitoring a switch with embedded RMON on each port, the TrafficDirector application can poll the switch directly for RMON information in the same way that it polls an agent.

Mini-RMON embedded in switches allows the TrafficDirector application to continuously monitor all ports on the switch while minimizing the performance impact associated with embedding complete RMON on each port. Mini-RMON provides vital statistics and alarms that can signal the application when a more detailed analysis is needed. The TrafficDirector application can use an external roving RMON agent to bring full RMON or RMON2 analysis to the suspect port.

Using VLAN Monitor

You can use VLAN Monitor to compare and contrast the statistics of all virtual local area networks (VLANs) learned by the TrafficDirector Configuration Manager from a Fast Ethernet agent on a SwitchProbe device, or VLAN Mode and VLAN Agents on the Network Analysis Module in which the VLAN monitor option has been enabled.

You can view data by:

• VLAN interface number---Up to 32 VLANs simultaneously on one screen.

You can change this value by editing the following line in the $NSHOME/usr/default.dvp file:

max-trafmon-agents:

• Traffic priority (up to eight priority levels simultaneously)---The number of priority levels (maximum of eight) that display on the VLAN monitor window are based on what has been learned by the particular SwitchProbe agent or switch from the traffic being monitored.

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Note You cannot change the maximum number.

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• Sorting the data to see either the number of packets or octets per second counted for a VLAN or priority level.

Starting VLAN Monitor (SwitchProbe Devices Only)

You can start VLAN Monitor from the Traffic level of the TrafficDirector main window.

To use VLAN Monitor, follow these steps:

Step 1 Click the Traffic radio button in the TrafficDirector main screen.

Step 2 Click the Agent or Switch radio button.

Step 3 Do one of the following:

• If you selected Agent, select an agent name from the agent list box.

• If you selected Switch, select a switch name from the switch list box. Then, select a switch port name from the interface list box (lower left of screen).

Step 4 Click the VLAN Monitor icon.

The VLAN Monitor window opens (Figure 13-1).

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Note If more than 32 VLANs have been learned, use the previous and next buttons on the bottom of the window to scroll through the display to see the additional VLANs.

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Figure 13-1: VLAN Monitor Window---VLANs

Understanding VLAN Monitor Displays

VLAN Monitor displays activity by VLAN number (Figure 13-1) or priority number. By changing the View option(s), you can customize the display to meet your needs.

Table 13-1 provides a description of the different VLAN Monitor displays that correspond to each of the View option(s).

Table 13-1: VLAN Monitor View Options

Select This View Option...	To Display
VLAN/Packets	The average packets and average non-unicast packets per second counted on a VLAN during the sample period you specified from the Refresh menu.
VLAN/Octets	The average octets and average non-unicast octets per second counted on a VLAN during the sample period specified from the Refresh menu.
Priority/Packets	The average packets per second counted on each particular priority level during the sample interval. You may display up to eight priority level bars.
Priority/Octets	The average octets per second counted on each particular priority level during the sample interval. You may display up to eight bars.

You can select the Priority display (Figure 13-2) from the View option in the menu bar. This display shows, at each priority level, the number of packets or octets seen by the agent or switch. If a priority level is not available, a priority level of zero is used.

Figure 13-2: VLAN Monitor Display---Priority Level

Posted: Mon Feb 8 15:02:39 PST 1999
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