TEP Pool and Multi Pod Migration

[Torsten_Graf]

Hi Buddys,

our customer is actually migrating his ACI Multi Pod (2 Pods) to new datacenterw.
Therefor the customer has bought new Leafs and Spines and has build a Multi Pod with 4 Pods.
After migration all components to the new dc's (Pod 3 and Pod 4) he wants to delete Pod 1 and Pod 2.
- Is it possible to delete POD 1? And yes, what about the TEP Pool from Pod 1 which is used by all 3 APICs?

Best Regards

Torsten

[AshSe]

Hey @Torsten_Graf 

Kindly note ->In a Cisco ACI Multi-Pod environment, each pod typically has its own TEP (Tunnel Endpoint) pool. When you add a new pod to the ACI Multi-Pod fabric, you assign a separate TEP pool for that pod. This means that the TEP pool for Pod 1 is not directly extended to the new pods (Pod 3 and Pod 4); instead, each new pod will have its own distinct TEP pool.

Key Points to Consider

1. Separate TEP Pools: Each pod in a Multi-Pod deployment has its own TEP pool. When you configure a new pod, you will assign a new TEP pool specific to that pod.

2. APIC Cluster: Ensure that the APIC controllers are distributed across the pods to maintain cluster quorum and high availability. If your APICs are currently in Pod 1, you will need to deploy additional APICs in the new pods before decommissioning Pod 1. Also, make sure that quorum (minimum 3 APICs) is maintained in the new Pods (Pod 3 & 4) before you decommission Pod 1 & 2.

3. Migration Process:

   1. Deploy New Pods: Set up and configure the new pods (Pod 3 and Pod 4) with their own TEP pools.
   2. APIC Controllers: Deploy additional APIC controllers in the new pods to maintain cluster quorum in Pod 3 &4.
   3. Migrate Workloads: Gradually migrate workloads and configurations from Pod 1 and Pod 2 to Pod 3 and Pod 4.
   4. Decommission Old Pods: Once the migration is complete, decommission the old pods (Pod 1 and Pod 2).

Steps to Migrate and Delete Pod 1 and Pod 2

1. Deploy New Pods:

   • Configure the new pods (Pod 3 and Pod 4) with their own TEP pools.
   • Ensure that the new pods are fully integrated into the existing ACI Multi-Pod fabric.

2. APIC Controllers:

   • Deploy additional APIC controllers in the new pods if necessary.
   • Ensure that the APIC cluster remains healthy and maintains quorum during the migration.

3. Migrate Workloads:

   • Gradually migrate workloads, EPGs, BDs, and other ACI constructs from Pod 1 and Pod 2 to Pod 3 and Pod 4.

4. Decommission Old Pods:

   • Remove the leaf and spine nodes from Pod 1 and Pod 2.
   • Update the APIC configuration to reflect the removal of the old pods.

5. Verify Fabric Health:

   • Thoroughly verify the health and stability of the ACI fabric after the old pods have been decommissioned.
   • Ensure that all policies, configurations, and workloads are functioning as expected in the new pods.

Important Considerations

1. Backup Configuration: Ensure that you have a complete backup of the ACI configuration before making any changes.
2. Testing: Perform thorough testing in a lab environment if possible, to validate the migration process.
3. Documentation: Follow Cisco's official documentation and best practices for ACI Multi-Pod deployment and migration.

[Torsten_Graf]

Hi AshSe,

thanks for the information, but in all white-papers it says, for moving APICs to other PODs to use TEP Pool 1 in the initial configuration. So how can I delete Pod 1 when they all reference to TEP Pool 1?

Therefor, even when I migrate all APICs to the new Pods, they still have a reference to the TEP Pool 1.

[AshSe]

Hi @Torsten_Graf , would it be possible for you to share link to the mentioned white papers. As per my understanding: 

for a Cisco ACI Multi-PoD setup, you should configure different TEP pools for each Pod to ensure proper operation and avoid IP conflicts.

[Torsten_Graf]

Hi @AshSe,

here is the link:https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739714.html#ConfiguringCiscoAPICforaMultiPodsetup

You can find this information in Table 1. "Cisco APIC fabric initialization configuration parameters"

Regards

[Remi-Astruc · Accepted solution]

Hi @Torsten_Graf ,

The decommissioning of Pod1 devices is possible, but you will need to keep Pod1 empty and visible because the seed TEP Pool is attached to it.

Keep Pod1 configured in the “Pod Fabric Setup Policy” in Fabric > Inventory. This is required because as mentioned, the APIC nodes continue to be addressed from the original TEP pool of Pod1.

Regards

[Torsten_Graf]

Hello @Remi-Astruc,

thanks for the information. I had already considered this solution as variant B, but then I probably won't be able to avoid it.

Regards