Spine-Leaf, Tier-3, or a Flat Switching Layer?

[JPScolar]

I have 2 x MX-250 in HA mode with  2 x 1Gb WAN uplinks and 10 x MS225-48 port switches. I don't know yet if the local traffic is more north-south or east-west and I'm trying to figure out the best switching design.

*  Do I need an additional aggregation switch, if so, what architecture will be more convenient?  Spine-Leaf or 3-Tier? 

*  What aggregation switch will be most appropiate, a MS425 (10Gb aggregation), using SPF+ ports as uplinks to the MXs (is this possible)?   

* Will it be a better idea to connect aal MS225 directly into the MXs using the SFP+ ports?

Thank you very much for your help. 

[alemabrahao]

Take a look at this documentation:  https://documentation.meraki.com/Architectures_and_Best_Practices/Recommended_Topologies/MX_and_MS_B...

[JPScolar]

Thank you for the pointer.  It is useful information.  My problem is that the Access Switches may be a bit of an overkill for the MXs and WAN uplinks and I'm trying to figure out the best possible design given these constraints.

[PhilipDAth · Accepted solution]

There is not quite enough info to say for sure.

Personally, I would take a pair of the MS225s, stack them together, and make them the core.  Plug the MX250s into them.  Plug all other MS225s into the network core.

If you want a 10Gbe core, I would buy a pair of MS425-16s and stack them together.  Then everything would plug into them instead.

https://meraki.cisco.com/product/switches/aggregation-switches/ms425-16/ 

[JPScolar]

Hi PhilipDath,   Thank you for the reply. That seems a interesting idea.  What will be the advantage of stacking, say 2 MS225, to build a core vs connecting all MS225 directly into the MX250s? 

[cmr]

The MXs don't participate in spanning tree or support any kind of port channels.  It is best to connect only two stacked switches to them and then branch out from there.  That way you can take advantage of both of the aforementioned features.