Cisco SDM (Switching Database Manager)

This topic is to discuss the following lesson:

In my years of working with multi-layer switches I never knew these templates existed, thanks!

Hi Emir,

Good to hear you learned something :slight_smile: Might be nice to check some of your production switches, see if their current SDM template is suitable for the job.



Do you know if nx-os has similar feature?


Hi Anuj,

It does, you can try the show hardware profile status command and the hardware profile command in configuration mode.


Hi @ReneMolenaar

I have couple of questions :-

Is SDM template just for TCAM or for both TCAM and CAM ? If it’s just for TCAM what is the need of storing unicast mac addresses since they are stored in CAM table ?

Does layer two switch have TCAM table ?

What are the uses of masks that used by unicast mac addresses, since mac address values need to be exact match to make forward decision ?

Hi Hussein,

It’s for both, you can verify this by looking at the SDM template and MAC address table of the switch:

SW1#show sdm prefer | include unicast mac
  number of unicast mac addresses:                  8K

SW1#show mac address-table count | include Space
Total Mac Address Space Available: 8048

An L2 switch still has a TCAM table, they can do things like access-lists where we also use the TCAM.

You can see the content of the TCAM table for L2 entries with show platform tcam table l2 detail or show platform tcam table mac-address detail.

For some MAC addresses, it shows the mask (FFFF.FFFF.FFFF) which is an exact match.

1 Like

Very useful extra information
thank you very much sir

Hi Renee,

Is there any specif models of Switch support SDM. I have tried vIOS L2 image in Eve-ng and could not run Sh SDM Prefer?


Got SDM command in Packet tracer. must be the image is not a multi-layer switch image. Can you please suggest what image I can use as Multi-layer switch in GnS3 or eve-ng.

Now in Packet tracer there is no Template under SDM prefer :frowning:

Hello Mohit

SDM is a feature that manages CAM and TCAM on a physical device. It doesn’t actually change the way a device will operate. Virtual devices on GNS3 don’t have CAM and TCAM, so there is nothing to manage. Remember GNS3 is an emulator, which means it runs real IOS operating systems on your computer hardware. The computer hardware doesn’t have CAM and TCAM, so the feature itself cannot function.

In order to see these features in action you will have to either use a simulator like Packet Tracer, which simulates the existence of these memory types and responds appropriately, (but only to a certain extent as you can see) or you must use real hardware.

Most L3 switches have this feature including the 3750, as well as the higher 4500/4600/9400 and 6500/6600/9600 series catalyst chassis switches.

You can find out more about SDM and GNS3 at this GNS3 forum thread.

I hope this has been helpful!