Dell Configuration Guide for the S4048–ON System 9.14.2.5

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Configuring CAM Threshold and Silence Period

This section describes how to configure CAM threshold and silence period between CAM threshold syslog warnings.

The CAM threshold and silence period configuration is applicable only for Ingress L2, IPv4, IPv6 and Egress L2, IPv4, and IPv6 ACL CAM groups. For other ACL CAM regions, the CAM threshold and silence period is fixed and the values are 90 percent and 0 respectively.

You can assign CAM threshold value using cam-threshold command to receive syslog messages when the CAM usage reaches the configured CAM threshold. The configured CAM threshold is a value specific to FP based on CAM features such as Ingress and Egress L2, IPV4, IPV6. The system checks the CAM usage of the features with the set threshold to display a syslog message, which contains the CAM region, slot/port-pipe and pipeline information. By default, syslog warning appears when the CAM usage is 90 percent.

You can also configure the silence period for the syslog message on the CAM usage. A syslog warning appears when the CAM usage exceeds the configured CAM threshold. The silence period starts after the initial syslog warning. The syslog warning does not appear until the silence period is active. By default, the silence period is 0 seconds.

Setting CAM Threshold and Silence Period

To configure the CAM threshold and silence period, use the following commands.

Assign the CAM threshold percentage
CONFIGURATION mode
cam-threshold threshold {default | threshold-percent}
The range of threshold value is from 1 to 100. The default threshold value is 90 percent.
Assign the silence period for syslog warning.
CONFIGURATION mode
cam-threshold threshold {default | threshold-percent} silence-period {default | silence-period-value}
The range of silence period is from 0 to 65535. The default is 0 seconds.

NOTE

If you delete a FP in a CAM region that is assigned with threshold, a syslog warning appears even during the silence period.

The system triggers syslog during the following events:

Re-configure the CAM threshold
Add or delete an ACL rule

Example of Syslog message on CAM usage

Following table shows few possible scenarios during which the syslog message appear on re-configuring the CAM usage threshold value.

Consider if the last CAM threshold was set to 90 percent and now you re-configure the CAM threshold to 80. And, if the current CAM usage is 85 percent, then the system displays the syslog message saying that the CAM usage is above the configured CAM threshold value.

Table 1. Possible Scenarios of Syslog WarningPossible Scenarios of Syslog Warning
Old CAM Threshold	New CAM Threshold	Current CAM Usage	Syslog
90	80	85	DellEMC(conf)#Nov 5 19:55:12 %S6000:0 %ACL_AGENT-4-ACL_AGENT_CAM_USAGE_OVER_THE_THRESHOLD: The Ipv4Acl cam region on stack-unit 0 Portpipe 0 Pipeline 0 is more than 80% Full.
90	95	91	DellEMC(conf)#Nov 5 19:55:12 %S6000:0 %ACL_AGENT-4-ACL_AGENT_CAM_USAGE_BELOW_THE_THRESHOLD: The cam-usage of Ipv4Acl cam region on stack-unit 0 Portpipe 0 Pipeline 0 is below 95%.
98	100	100	No syslog
95	80	10	No syslog
92	90	89	No syslog