What is better for LAN design ? Layer 2 or Layer 3 !!

Hythim Ali El Hadad · ‎07-23-2016

Hi,

We have a new network with 2 core switches as N7K and 4 distributions as 4500X and a lot of Edges

Is better to configure int vlans on Core and all network as Layer 2 with STP

Or to configure int vlans on Distribution SWs and to configure dynamic routing protocol as OSPF between them

I think the second solution will offload the routing from Core and may enhance the convergence time !!

Thanks for your advise

Regards

Haitham

ahmedshoaib · ‎07-23-2016

Hi;

If you follow the Cisco Core, Distribution & Access Layer design; then you need to core all SVI on your distribution switch & from distribution to Core you need to run Layer 3 (Which is a recommend design) to restrict the STP & L2 till distribution layer.

While If you want to fallow the Collapsed Core design; then you can configure the SVI's on Core Nexus 7K and 4500X will be completely Layer 2. (2nd design is also valid but you need to extra care with reference to STP.)

Thanks

Shoaib Ahmed

Hythim Ali El Hadad · ‎07-23-2016

Thanks Shoaib for your reply

And what is better for convergence time ?