Configuring SNMP Alarms for rate limiting

NetScaler appliances such as the NetScaler MPX 10500, 12500, and 15500 are rate limited. The maximum throughput (Mbps) and packets per second (PPS) are determined by the license purchased for the appliance. For rate-limited platforms, you can configure SNMP traps to send notifications when throughput and PPS approach their limits and when they return to normal.

Throughput and PPS are monitored every seven seconds. You can configure traps with high-threshold and normal-threshold values, which are expressed as a percentage of the licensed limits. The appliance then generates a trap when throughput or PPS exceeds the high threshold, and a second trap when the monitored parameter falls to the normal threshold. In addition to sending the traps to the configured destination device, the NetScaler logs the events associated with the traps in the /var/log/ns.log file as EVENT ALERTSTARTED and EVENT ALERTENDED.

Exceeding the throughput limit can result in packet loss. You can configure SNMP alarms to report packet loss.

For more information about SNMP alarms and traps, see “Configuring the NetScaler to generate SNMP v1 and v2 Traps.”

This document includes the following details:

• Configuring an SNMP Alarm for Throughput or PPS
• Configuring SNMP Alarm for Dropped Packets

Configuring an SNMP alarm for throughput or PPS

To monitor both throughout and PPS, you must configure seperate alarms and set threshold pps value in Mbps.

To configure an SNMP alarm for the throughput rate by using the command line interface

At the command prompt, type the following commands to configure the SNMP alarm, set threshold value in Mbps and verify the configuration:

• set snmp alarm PF-RL-RATE-THRESHOLD [-thresholdValue <positive_integer> [-normalValue <positive_integer>]] [-state ( ENABLED | DISABLED )] [-severity <severity>] [-logging ( ENABLED | DISABLED )]
• show snmp alarm PF-RL-RATE-THRESHOLD

Example

> set snmp alarm PF-RL-RATE-THRESHOLD -thresholdValue 70 -normalValue 50

To configure an SNMP alarm for PPS by using the command line interface

At the command prompt, type the following commands to configure the SNMP alarm for PPS and verify the configuration:

• set snmp alarm PF-RL-PPS-THRESHOLD [-thresholdValue <positive_integer> [-normalValue <positive_integer>]] [-state ( ENABLED | DISABLED )] [-severity <severity>] [-logging ( ENABLED | DISABLED )]
• show snmp alarm PF-RL-PPS-THRESHOLD

Example

> set snmp alarm PF-RL-PPS-THRESHOLD -thresholdValue 70 -normalValue 50

To configure an SNMP alarm for throughput or PPS by using the GUI

1. Navigate to System > SNMP > Alarms, and select PF-RL-RATE-THRESHOLD (for throughput rate) or PF-RL-PPS-THRESHOLD (for packets per second).
2. Set the alarm parameters and enable the selected SNMP alarm.

Configuring SNMP alarm for dropped packets

You can configure an alarm for packets dropped as a result of exceeding the throughput limit and an alarm for packets dropped as a result of exceeding the PPS limit.

To configure an SNMP alarm for packets dropped because of excessive throughput, by using the command line interface

At the command prompt, type:

set snmp alarm PF-RL-RATE-PKTS-DROPPED [-state (ENABLED | DISABLED)] [-severity <severity>] [-logging ( ENABLED | DISABLED )]

To configure an SNMP alarm for packets dropped because of excessive PPS, by using the command line interface

At the command prompt, type:

set snmp alarm PF-RL-PPS-PKTS-DROPPED [-state (ENABLED | DISABLED)] [-severity <severity>] [-logging ( ENABLED | DISABLED )]

To configure an SNMP alarm for dropped packets by using the GUI

1. Navigate to System > SNMP > Alarms, and select PF-RL-RATE-PKTS-DROPPED (for packets dropped because of excessive throughput) or PF-RL-PPS-PKTS-DROPPED (for packets dropped because of excessive PPS).
2. Set the alarm parameters and enable the selected SNMP alarm.