Cisco ACI Multi-POD with Local L3-Out

[harshal.shahane]

Hello,

Is it possible to deploy ACI Fabric in Multi-POD with option to utilise local L3-Out (local to POD).

If so, what parameters needs to be configured?

Thanks in advance.

Regards,

Harshal

[Rick1776]

From my understanding the IPN network is only for APIC control plane traffic for the ACI fabric for POD to POD communication.

For other L3 traffic you would use the local L3-Out.

Please see the ACI Multi-POD whitepaper for details.

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-737855.html#_Toc463058887

[Rick1776]

Sorry, I miss read your question from before. You cannot deploy a Multi-POD environment via L3Out's you need a dedicated IPN (Inter Pod Network).

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-737855.html#_Toc463058887

[harshal.shahane]

Hello Rick,

Thank you for your response.

Yes I am deploying an IPN to establish Multi-POD Environment.

My query is regarding whether by default in Multi-POD environment the Local L3-Out is preferred? As the business requirement is for not allowing production traffic to pass through the IPN devices.

Regards,

Harshal Shahane

[Rick1776]

You can steer the traffic however you want it to go. So for instance any production data you can create a L3out and a vrf for that. The IPN control plane always has to use the IPN network. If the IPN network fails data is still processed through the ACI network but you won't be able to make any changes to the ACI fabric tell the IPN is back online.

The Cisco documentation is a little laking for ACI Multi-POD. I would check out Cisco Live presentations that have a little more substance.

https://www.ciscolive.com/global/on-demand-library/?search=Multi-Pod#/session/1485287126408001gMwX

https://www.ciscolive.com/global/on-demand-library/?search=Multi-Pod#/session/1495472500418001QKzj

[Oleksii Dolgopolsky]

Hello folks,

I have similar question.

So, if I would have 2 Data Centers with ACI MultiPod, each Pod (or DC in particular) have their own connection to WAN and Internet, and both DCs work in Active/Active manner.

When my particular VM1 moves from DC1 to DC2, will the ACI fabric recalculate routing in such way to advertise that route to VM1 from DC2 WAN headend and stop advertise from DC1? Does it work out of the box with some configuration from GUI?

Thanks.

[Nuno Marques]

Hi,
You will need GOLF for host route advertisement.
When you use GOLF your /32 from your vm will be advertised from the POD where the vm is attached to the WAN providing ingress traffic optimization.

If tou are not using GOLF the BD subnet will be advertised from both PODs.

[Rick1776]

You can specify traffic to go onlver the IPN network instead of the local L3 out. For instance I have a customer with Multi-POd that steers all vomotion over the IPN links and others use the L3 out in the common tenant.

[jachbr]

Can you explain how you are specifying traffic to go over the IPN as opposed to the local L3 Out? 

Thank you

[Rick1776]

Typically you would create a separate L3out for the IPN network, a BD for the Vmotion/VLAN, and associate that with the Application Profile.You can do this via the common tenant if needed.

[wojtek.siodelski]

This white paper confuses me a little bit as I have the following use case.

- 2 sites that are connected via Virtual Stack 9500 switches with Dark Fibre Between them

- LAN/WAN connects to Virtual Stack which means that IPN network would basically be across that existing connection

- L3 OUT from the Border Leafs would provide connectivity from 9500 Virtual Switches using BGP

Based on this White Paper I would also need a dedicated connection from the Spines to the Same Switches running OSPF?

Are you saying I need to have dedicated Interconnect between both sites that goes outside of this existing setup?

[harshal.shahane · Accepted solution]

Dear All,

Thanks a lot for your response,

In this scenario we went ahead with deploying a separate Tenant altogether for the second POD. 

As in this scenario, the multi-POD was used for DC-DR in Active-Passive.

Regards,

Harshal