mutli-fabric bgp-evpn with local egress

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Are there any major design constraints or limitations that would prevent two separate CLOS fabrics from sharing a single BGP-EVPN Control plane? The design goal here is to provide L2 extension across datacenters for VM mobility (DCI). A secondary goal is to provide local egress from VNIs to local gateways egressing the fabric. 

I am fairly certain that this can be accomplished with Cisco ACI and the multi-site topology model, which leads me to believe that it is also possible with Cumulus. 

I realize this is a very oversimplified question that requires a complex answer. Hoping for a generalized answer before I spend too many cycles researching and building out a GNS3 lab to test.  

thanks in advance. 
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Adrian Oden

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Posted 2 months ago

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Pete B, Official Rep

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Hi Adrian, I spoke to one of our engineers and he confirmed we support this. "Same evpn control plane can be extended between two datacenter fabrics. However, we do not support the multi-site draft (supported in Cisco nexus) yet." Does this help?
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Adrian Oden

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Thank you, Pete. I assume that you are referring to draft https://tools.ietf.org/html/draft-sharma-multi-site-evpn-00. Do you know if there is any roadmap to implement this draft to the product?
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Eric Pulvino, Official Rep

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Pete was referring to a single shared EVPN domain across the DCI. This is of course fully supported in Cumulus Linux today (v3.4+). The Multi-site draft you referred to which further segments the EVPN domain and allows for the isolated reuse of VNI namespace is not supported today. From talks with the development engineers on the topic, there would likely be some support of the feature in hardware that would need to be present.