Cisco Old ACI Fabric to New ACI Fabric l2 migration

[suraj sutar]

Hello Team,

We are going to migrate cisco old ACI to New ACI Fabric l2 migration.

1) Can we perform migration like l2 or how?

2) Anyone have done this type of migration please share steps.

Thanks 

Suraj Sutar

[Sergiu.Daniluk]

Hi @suraj sutar 

What type of migration you have in mind? Build the new fabric and migrate the servers from old fabric to new one? Or add the new devices to old fabric and decommission the old one afterwards?

Also, what hw model you have in old fabric and new fabric?

Take care,

Sergiu

[suraj sutar]

Hello @Sergiu.Daniluk 

We are building new ACI fabric. we want to migrate the server via l2 out with the existing ACI fabric.

[Robert Burns]

There's plenty of Information available on the web regarding ACI migrations.   We're happy to help with specific questions, but you need to do your own research/homework as well.  Start with https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/migration_guides/migrating_existing_networks_to_aci.html

Robert

[suppor.nts]

hello ,

did you successfully migrated?

and if yes , what is the approach you did?

thanks

[suraj sutar]

Hello,

No, it's not worked, we have put one switch between two fabrics and then
migrated

[shawnkarthick]

Hi Suraj,

we have a similar scenario, Migrating the Workloads from old ACI fabric(with old HW) to new ACI Fabric(new HW and latest version). let us know if back-to-back connectivity between old and new ACI fabric is a supported approach and was there any challenges.

• Adding the new APIC to existing fabric its not possible considering the below scenarios
• Plan to upgrade 5.3(2) version, current version is 2.2(4p/q/r)
  • Existing switch models(N9k-C9396PX ,N9k-C9336PQ) and old APIC M1 does not support 5.3(2) version 
  • https://www.cisco.com/c/en/us/td/docs/Website/datacenter/apicmatrix/index.html#cur=2.2(4p/q/r)&tar=5.3(2)
  • Also Recommended upgrade path is to upgrade first to 4.2(7) and then go to 5.3(2)
    • Which requires two windows to complete the upgrade

[akhil kamalakaran]

Last week we successfully migrated to new APIC box. We followed below link.

Cisco APIC M1/M2/M3/L1/L2/M3 to M4/L4 Cluster Migration, Release 5.3(1) - Cisco

[AshSe]

Hello Suraj,

Kindly be noted that migrating an old network to ACI fabric requires L2Out connectivity and there are two types of L2Out connectivity:

1. L2Out EPG-Extension
2. L2Out BD-Extension

Feel free to ask any specific question.

[RedNectar]

Firstly, for a question that is 2 years old I really don't think adding more comments is going to help anyone.

In particular, I have to clarify @AshSe 's last response

---

Kindly be noted that migrating an old network to ACI fabric requires L2Out connectivity and there are two types of L2Out connectivity:

1. L2Out EPG-Extension
2. L2Out BD-Extension

---

Firstly, be aware that there is a construct in a Tenant config called "L2Out" which behaves a little like an Application EPG but is restricted to a single VLAN.

My advice is to Never use a L2Out - there is nothing that a L2Out can do that is not able to be done by a regular Application EPG, and Application EPGs are way easier to configure - which is what @AshSe is referring to by option 1 above. Option 2 would involve using the abominable L2Out.

I've written more about L2Outs on this forum.

https://community.cisco.com/t5/application-centric-infrastructure/aci-l2out-vs-l2extension/m-p/4043695/highlight/true#M7945

https://community.cisco.com/t5/application-centric-infrastructure/aci-vlan-pool-aaep-and-domain-best-practises/m-p/4756185/highlight/true#M13440

https://community.cisco.com/t5/application-centric-infrastructure/aci-physical-domain-and-l2out-domain/m-p/4164371/highlight/true#M9286

https://community.cisco.com/t5/application-centric-infrastructure/aci-physical-domain-and-l2out-domain/td-p/4164103

https://community.cisco.com/t5/application-centric-infrastructure/quick-question-about-l2out/td-p/4909406

https://community.cisco.com/t5/application-centric-infrastructure/vlan-configuration-for-aci-l2out/td-p/4799412

https://community.cisco.com/t5/application-centric-infrastructure/why-to-use-l2-external-domain-association-for-application-epg/td-p/5064217

[AshSe]

Dear @RedNectar 

Greetings and with all due respect, I don't see any offence in addressing any previously addressed question as long as technology is not declared obsolete.

I went through all your previous posts w.r.t. L2Out and understand that you are absolutely against using L2Out for any Old, non-ACI to ACI fabric migration. 

I have established my fair understanding and to me L2Out looks logical. At the same time I tried understanding your logic of using Application EPG but couldn't understand the same. It looks I need to share & discuss my L2Out-Extension lab workbook with you.

May I request you to present your understanding with diagrams to understand. Please take a look (PFA) my understanding about L2Out-BD Extension for Old to ACI Migration. 

I hope you will be able to understand my diagrammatic presentation of the L2Out lab.