ACI SPAN - TCAM utilization identification

[nileshgore25]

Hi ACI Gurus,

I want to understand how to check the TCAM utilization on ACI Leaf switch.

I found below information but not able to correlate altogether. 

The following link shows that for Nexus 9300 switch the default TCAM allocation, SPAN is assigned one slice of 256 bytes.
https://www.cisco.com/c/en/us/support/docs/switches/nexus-9000-series-switches/119032-nexus9k-tcam-00.html

The Cisco verified scalability guide shows the maximum number of TCAM entries and also the formula to calculate the TCAM entries.

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/4-x/verified-scalability/Cisco-ACI-Verified-Scalability-Guide-412.html#id_110983

Maximum number of SPAN ACL filter TCAM entries: 

• IPv4: 480

• IPv6: 240

Total number of TCAM entries is calculated using the following formula:

(IPv4-filters) * (IPv4-filter-source-groups) + 2 * (IPv6-filters) * (IPv6-filter-source-groups) + 2 * (no-filter-source-groups)

I also know this command which gives some clue about the SPAN sessions.

leaf# vsh_lc
module-1# show system internal aclqos span summary | grep SSN
SSN 9 hdl 0x10f1299c dst_type ERSPAN(2) nsrcs 0 flags 0x0
Total SSNs: 1 nSrcs 67 nSrcsUP 67
module-1#

Can someone please help how to interpret this and identify the current TCAM utilization of the ACI LEAF switch ?

[Sergiu.Daniluk]

Operations -> Capacity Dashboard -> Leaf Capacity

Stay safe,

Sergiu

[egoepfert]

Is it the 'Policy CAM' field that we're looking at for the TCAM stats?

[Sergiu.Daniluk]

Exactly!

[nileshgore25]

@egoepfert , Thank you for your response.

Policy CAM is not same as TCAM per the blog on the URL mentioned below.
https://unofficialaciguide.com/2021/01/06/understanding-aci-tcam-utilization-optimization/

My Aim to identify the TCAM space is to check if the SPAN TCAM space is reaching its capacity by addition of the new SPAN config on the ToR.

However I will rephrase my question and open a new post.