Cisco iCAM Monitor

Overview

Cisco iCAM – intelligent CAM (Content Addressable Memory) Analytics and Machine learning is a feature available on Cisco Nexus switches. It provides functionalities focused on resource monitoring and analysis for various switch functions and features like;

  1. ACL TCAM entries
  2. ACL TCAM resource utilization
  3. Forward information base(FIB) TCAM resource utilization
  4. Layer 2 Switching
  5. Unicast routing
  6. Process memory
  7. Shared memory
  8. Multicast routing

Cisco iCAM Benefits

iCAM provides resource monitoring and analytics for different functions and features on supported switches. It keeps an eye on utilization levels, when usage approaches a predefined limit (default or user defined) it raises an alert through system logs to notify the network administrator.

  • Network Visibility – Improved network visibility with insights into traffic patterns, resource usage and predicting scale.
  • Identify Potential Bottlenecks – Understanding the TCAM usage per feature and view of traffic & usage analytics per feature enables you to proactively plan capacity by identifying potential bottlenecks and scaling requirements.
  • Prevent Outages – Reduced risk of network outages by receiving alerts on critical resource utilization levels.
  • Align with Verified Scale Numbers – Verify, detect, plan, and predict your environment against Cisco-verified scale numbers or customized scale numbers threshold.
  • Optimize Resource Allocation – Efficient management of switch resources by understanding per-feature hardware usage.
  • Historical Analytics – iCAM’s historical traffic analytics provide valuable insights into network behavior and resource utilization. This information helps network administrators make informed decisions about network management, capacity planning, and troubleshooting
  • Predicting Traffic Analytics – iCAM’s traffic prediction capability is a powerful tool for network administrators. By leveraging historical data and machine learning, it helps anticipate future traffic demands and optimize network resource allocation.

*** Beginning with Cisco NX-OS Release 9.3(5), iCAM feature is always enabled and users cannot disable the feature

*** Scale monitoring is based on two hours polling interval by default, configurable to one hour (range 1 – 24 hrs)

https://www.cisco.com/c/en/us/td/docs/dcn/nx-os/nexus9000/103x/configuration/icam/cisco-nexus-9000-series-nx-os-icam-configuration-guide-release-103x.pdf

Configuration

iCAM core functionalities are typically enabled by default and cannot be entirely disabled. However, there are still configuration options available to customize how iCAM operates in your network.

  • Setting User Defined Custom Limits – iCAM comes with default thresholds for various functions but you can adjust these to better suit your specific needs so that you will have a custom sensitivity for critical functions by lowering limits to trigger alerts sooner. Also reduce alert frequency for less critical functions by raising limits.
Nexus-1(config)# icam monitor scale vxlan bgp underlay-mcast-group limit 512
  • Changing the configured scale value does not alter the actual supported value of the hardware or software. The configured scale value acts as a benchmark against which iCAM compares resource utilization. By setting thresholds based on the configured scale value, you determine when iCAM triggers alerts.
  • Supported Value: This is the fixed, verified limit for a particular function or resource on your specific Cisco Nexus switch hardware and software combination. These limitations are established by Cisco through rigorous testing.
  • Defining Specific Features or Resources to Monitor

The following are example commands used to configure iCAM entries, resources, system for a module on the Cisco Nexus 9000 Platform switches:

Leaf-5(config)# icam monitor entries acl module module-number inst inst-number  
Leaf-5(config)# icam monitor resource fib-tcam module module-number inst inst-number  
Leaf-5(config)# icam monitor system 
Leaf-5(config)# icam monitor system threshold info 70 warning 80 critical 90

Config example for scale monitoring

Leaf-5(config)# icam monitor scale ?
  <CR>               
  l2-switching       Layer 2 switching
  multicast-routing  Multicast routing
  threshold          Change percent threshold limit
  unicast-routing    Unicast routing
  vxlan              VxLAN
Leaf-5(config)# icam monitor scale multicast-routing routing-forwarding route-v4 limit 32000

Link to check supported features – https://www.cisco.com/c/dam/en/us/td/docs/Website/datacenter/platform/platform.html

Show Commands

By utilizing these “show” commands effectively, you can gain valuable insights into your network resource utilization, identify potential bottlenecks, and leverage historical data for proactive network management. Show commands can be used to get detailed information about entries for a specific resource type, to get insights into the utilization of TCAM (Ternary Content Addressable Memory) resources for a specific module and instance within the switch, to displays historical traffic statistics for the entries of a specific resource type, or to displays details about scale monitoring, including configured thresholds and actual utilization levels for various resources compared to Cisco-verified scale limits.

Sample show outputs

Leaf-5# show icam ?
  entries     TCAM Entries with result and stats
  health      Health status
  prediction  Machine learning prediction
  resource    TCAM Resource utilization
  scale       Verified scale
  system      System resources utilization

Leaf-5# show icam  scale ?
  <CR>               
  >                  Redirect it to a file
  >>                 Redirect it to a file in append mode
  history            Show scale history
  l2-switching       Layer 2 switching
  multicast-routing  Multicast routing
  thresholds         Show thresholds statistics
  unicast-routing    Unicast routing
  utilization        Show utilization statistics
  vxlan              VxLAN
  |                  Pipe command output to filter

Leaf-5# show icam  scale vxlan thresholds 
==================================================
Info Threshold =  80 percent (default)           |
Warning Threshold =  90 percent (default)        |
Critical Threshold = 100 percent (default)       |
All timestamps are in UTC                        |
==================================================

--------------------------------------------------------------------------------
------------------------------------------------------------------
Scale Limits for VxLAN
--------------------------------------------------------------------------------
------------------------------------------------------------------
                  Feature  Verified    Config    Current     Info             La
st Info   Warning          Last Warning  Critical         Last Critical
                              Scale     Scale      Scale     Exceeded    Exceede
d Timestamp  Exceeded    Exceeded Timestamp  Exceeded    Exceeded Timestamp
--------------------------------------------------------------------------------
------------------------------------------------------------------
                  BGP VNI      2000      2000         5         0               
      -         0                     -         0                     -
  BGP SVI with Anycast GW      2000      2000         5         0               
      -         0                     -         0                     -
                  BGP VRF       900       900         4         0               
      -         0                     -         0                     -
          BGP Mcast group       512       512         2         0               
      -         0                     -         0                     -
                 BGP VTEP       512       512         4         0               
      -         0                     -         0                     -
                  BGP MAC     64000     64000         0         0               
      -         0                     -         0                     -
      BGP IPv4 host route     60000     60000         0         0               
      -         0                     -         0                     -
      BGP IPv6 host route      7000      7000         0         0               
      -         0                     -         0                     -
       BGP IPv4 LPM route     12000     12000         8         0               
      -         0                     -         0                     -
       BGP IPv6 LPM route      7000      7000         0         0               
      -         0                     -         0                     -
         BGP VLAN port VP     10000     10000         3         0               
      -         0                     -         0                     -
         BGP VLAN per FEX        75        75         0         0               
      -         0                     -         0                     -
           BGP IGMP group      8192      8192         0         0               
      -         0                     -         0                     -

While iCAM itself doesn’t use chord diagrams, the data it collects can be used to generate chord and other visualizations that can help you understand your network resource utilization patterns.

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