TCAM, CAM and SDM prefer

[iurie.bogdanovici]

Hello.

On catalyst 3750 there are 4 SDM templates: default, routing, access and vlan. From what I understand SDM is used to split the TCAM into areas. Depending on your needs you will use one of the templates. My question is about VLAN SDM template. This template will support more MAC addresses. But i thought that this is the job of the CAM table to keep MAC addresses. Where is it located the MAC address table, in CAM hardware or TCAM? I know that TCAM is used to store security and QOS ACLs, netflow data and FIB table. But I didn't think that TCAM could be used for MAC lookups.

[Cisco Freak]

Hi,

With the VLAN SDN template, the TCAM can hold up to 12K mac addresses. Please refer the below link for more info

http://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/44921-swdatabase-3750ss-44921.html

CF

[iurie.bogdanovici]

I've read this, but what about CAM table. In my understanding TCAM is mainly used for QoS and ACL lookups, not for MAC lookups. MAC lookups stay in CAM. In this case why do we need TCAM to store MAC addresses?

[Cisco Freak]

Hi,

Go through this link. It should clear all your queries.

https://supportforums.cisco.com/document/60831/cam-content-addressable-memory-vs-tcam-ternary-content-addressable-memory

CF