ACI Browfield - from two Single Pods to Multi Site

[AdrianT]

Hello Team,

We want to move from Single Pod ACI Fabrics to Multi Site.

My questions are the following:

1). Some of the VLANs would need to be stretched between the two sites (the VLANs that need to be streched are already present in the two sites). What is the best possible way to achieve that? Before sharing my thoughts on how I think this should be done, I would appreciate your thoughts on this topic?

2). Some other VLANs need to belong only to either Site 1 or Site 2. What is the best way to achieve that? Would using import only in the Template would solve it?

Thank you.

[AdrianT]

Hello,

Wanted to check if is there any answers to the above?

[Manuel Velasco]

Hi Adrian,

When stretching the connectivity between sites, you are not actually stretching the VLAN; you are stretching the VRF, BD, or EPG. The encapsulation VLAN in ACI is used solely for classification purposes. In other words, you could stretch an EPG where, at site 1, you have one VLAN to classify the endpoints, and at site 2, you can have a different VLAN to classify the endpoints and this would still be okay.

If your plan is to stretch an EPG that already exists on both sites but you want to extend their connectivity via the ISN, then you need to consider the naming assigned to each EPG on each site. If the names are different, NDO would stretch each EPG independently.

For your second question, again you don't stretch the VLANs, so they don't play a role when stretching the connectivity between sites.

Thank you.

[AdrianT]

Hi @Manuel Velasco in this situation if both fabrics are already in use, if I stretch the EPG/BD/VRF between the two sites which are found already in the two sites, will that have impact on the customer, or can I do it anytime since there should not be any impact?

[Manuel Velasco · Accepted solution]

This is not an easy question, as one must first understand your current deployment and know how you plan to use NDO to extend connectivity between sites. When it comes to brownfield deployments, you must create the tenant on NDO and Import the configuration in NDO.  You must also keep in mind that if you want NDO to stretch connectivity between EPGs in two different sites that were not originally deployed by NDO, you need to ensure that the Tenant's name, Application profile name, VRF's name, BD's name, and EPG's name are identical at both sites. If these names are not identical, you cannot stretch these already existing objects, as NDO will see them as different objects.

Take a look a the link below that talks about brownfield imports.  

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739609.html#ImportingexistingpoliciesfromCiscoAPICintoCiscoNexusDashboardOrchestrator

[AdrianT]

@Manuel Velasco I was thinking exactly the same as you mentioned above here. You just confirmed my understanding. Our setup in the drawing is the one on the right. Will also take a look at the pointed documentation.

Thank you.