Pre-provision config on ACI - vpc

[rohandec1980]

Hi all

We are planning a migration of a dual ACI fabric to a multipod. The non-seed pod has a large number of servers connected in a vpc. Migration plan is as below:

1. Move the odd numbered switches every vpc domain(we have around 5  pairs of switches) to the multi-pod setup.

2. Configure the fabric for single link - interface policy group (IPG), configure the interface profile and associate with the individual switch profile, setup static bindings for the single leaf interface in the EPG.

3. Move the servers to the multipod setup. 

4. Move the even numbered switch, configure the vpc-IPG and configure the interface profile and associate with the switch profile for the leaf switch pair.

The problem with this approach is that we need to configure the ACI multipod fabric twice and there would be 2 downtime windows to the setup (one to move the servers to the multipod setup and other to re-configure them in vpc).

Want to confirm if:

1. Is there a way i can pre-provision the vpc without the leaf switches being configured or discovered ( i know the node-ids that will be assigned to the switches and the serial numbers )? Using the REST API as GUI doesn't offer this option.

2. The vpcs would come up when one of the leaf in the vpc domain is connected to the fabric and discovered?

Regards

Rohan

[lalmouaz]

In your case, Each site is a separate ACI fabric managed by its own APIC cluster. Usually changing from one design option to the other at a later stage would be disruptive.

Taking one site and joining it as a pod to another site is disruptive process. So in your case, you would need to wipe the config on all the devices and add it as a 2nd pod to the other site.
Other option is you can add multi-site and use the MSO  to manage tenant polices extended across sites.

But the decision of multi-pod vs multi-site should be made based on use cases and requirements.