Configuring TCAM Threshold Based Alarms

The Ternary Content-Addressable Memory (TCAM) threshold based alarms feature generates syslog and consequently a Simple Network Management Protocol (SNMP) trap when an application reaches the preset threshold for its allotted TCAM size. Alarms and traps are generated when the threshold value for the TCAM is reached.

Configuring TCAM Threshold Based Alarms

The Ternary Content-Addressable Memory (TCAM) threshold based alarms feature generates syslog and consequently a Simple Network Management Protocol (SNMP) trap when an application reaches the preset threshold for its allotted TCAM size. Alarms and traps are generated when the threshold value for the TCAM is reached.

Information on TCAM Threshold Based Alarms

This feature generates a Syslog and consequently an SNMP trap when the number of entries for an application on TCAM becomes equal to or greater than the threshold percentage of the value defined in the license template. You can configure the threshold percentage value for notification before the TCAM limit specified by the license for an application is exhausted. The default threshold value for all TCAM applications is 80 percent. The frequency of the alert messages is rate limited to avoid flooding the router console when many entries are added or deleted in quick succession.


Note

This feature can be enabled or disabled using the platform tcam-threshold enable or no platform tcam-threshold enable command.

Information on TCAM Threshold Based Alarm Frequency

This feature enables you to configure the frequency at which the TCAM Threshold Based alarm should be generated. You can configure the TCAM Threshold Based alarm frequency only if you have enabled the TCAM Threshold Based alarms.


Note
By default, the platform tcam-threshold alarm-frequency command appears in the router configuration file with the default alarm frequency value 1.

Configuring TCAM Threshold Based Alarms

To configure TCAM threshold based alarms, complete the following steps:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. platform tcam-threshold enable [app-name | all] [threshold_percentage | default]
  4. platform tcam-threshold alarm-frequency [frequency-value | default]
  5. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Router> enable
Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

platform tcam-threshold enable [app-name | all] [threshold_percentage | default]

Example:

Router(config)# platform tcam-threshold enable all 75

Enables TCAM threshold based alarms. To disable, use the no platform tcam-threshold enable command.

  • app-name—Specifies the name of an application.

  • all—Selects all applications supported on the router.

  • threshold_percentage—Specifies the threshold percentage.

  • default—Uses the default threshold of 80 percent.

Step 4

platform tcam-threshold alarm-frequency [frequency-value | default]

Example:

Router(config)# platform tcam-threshold alarm-frequency 75

Configures the TCAM Threshold Based alarm frequency

  • frequency-value—Specifies the frequency [1 - 75] at which the alarm should be generated per hour.

  • default—Sets the default value 1.

Step 5

end

Example:

Router(config)# end

Returns to privileged EXEC mode.

Verifying TCAM Threshold Based Alarms

  • Use the show platform hardware pp active tcam utilization app-name detail asic-id command to display the TCAM utilization for the applications.

    Following is a sample output using the show platform hardware pp active tcam utilization command to display the TCAM utilization for ACL application on ASIC 0: 

    Router# show platform hardware pp active tcam utilization acl detail 0
    Tcam Utilization per Application and Region
ES == Entry size == Number of 80 bit TCAM words

App/Region  Start   Num Avail ES Region Range  Used   Range Num Used 
---------------------------------------------------------------------------------------------------
ACL         0xc000  0x0800    2  000000 000000 000000 000000 166 

Scale limit: 2000
Threshold configured: 0%
Current usage: 166 (8% approx.)

  • Use the show platform hardware pp active tcam usage command to display the alarm status for the applications: 

    Router# show platform hardware pp active tcam usage
    TCAM Size: Num of 80 bit entries: 0x010000, Number of Blocks: 16

Tcam Application Table
New Column
Thld Alarm State = 1 if Threshold alarm raised, 0 if alarm cleared

App/Region            Start Index      Num Entries      Entry Size       Num Regions      Profile ID       Blk_sel_bits4    Bsb3             Bsb2             Bsb1             Thld Alarm S...  
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
UCASTV4               000000           0x3000            1                34               19                        0                0                	0             0x7       	1                
MCASTV4               0x3000           0x1000          	 2               109                4                        0                0                	0             0x18      	0                
INGRESS_VLAN_TRANS    0x5000           0x1000           	1                25               16                        0                0                	0             0x20       0

Feature Information for TCAM Threshold Based Alarms

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1. Feature Information for TCAM Threshold Based Alarms

Feature Name

Releases

Feature Information

TCAM Threshold Based Alarms

Cisco IOS XE Release 3.14.0S

This feature was introduced on the Cisco ASR 920 Series Aggregation Services Router (ASR-920-12CZ-A, ASR-920-12CZ-D, ASR-920-4SZ-A, ASR-920-4SZ-D, ASR-920-10SZ-PD, ASR-920-24SZ-IM, ASR-920-24SZ-M, ASR-920-24TZ-M) .