Why to use L2 External Domain Association for Application EPG?

[Evgeniy]

Hello everyone,

When we configure L2Out we use L2 External Domain (with proper VLAN pool). When we use extension of existing Application EPG with the Static Path binding we use Physical Domain (with proper VLAN pool). But why do we need L2 External Domain Association (this option is also available) for the Application EPG? Is it just for using the same way as we use Physical Domain? So, is there any difference between Physical Domain Association and L2 External Domain Association?

Thanks!

[RedNectar · Accepted solution]

Hi @Evgeniy 

When we configure L2Out we use L2 External Domain (with proper VLAN pool). When we use extension of existing Application EPG with the Static Path binding we use Physical Domain (with proper VLAN pool). But why do we need L2 External Domain Association (this option is also available) for the Application EPG? Is it just for using the same way as we use Physical Domain? So, is there any difference between Physical Domain Association and L2 External Domain Association?

Thanks!

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The function of a Physical Domain and a L2 External Domain is the same. Cisco should never have created an object for a L2 External Domain.  But essentially the idea was the a L2External Domain was to be used for L2Outs, and a Physical Domain for all static mappings.

I've expressed a more honest opinion of L2 External Domains and L2Outs in this answer to a similar question