topic Re: Adding or changing the stack topology after LAN automation in Software-Defined Access (SD-Access)

Adding or changing the stack topology after LAN automation

ianjgrant — Fri, 06 Aug 2021 14:31:58 GMT

Hi Folks

I'm deploying a new SDA network, primarily to serve wireless APs, but also setting the foundation for a wired network upgrade too. I've deployed Fusion & Border switches (Cat 9500) and single edge switches (Cat 9300L), and all is good. Each Edge has a uplink to both Borders. At a later date I plan to stack new switches to the existing Edges, as a 'phase 2' project.

At that time, I'd also like to move one uplink to a different switch in the stack. ie initially uplinks will be Te1/1/1 and Te1/1/4. Once the extra stack members are added I'd like to use Te1/1/1 & 3/1/1 for example.

The LAN automation guide - https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/tech_notes/b_dnac_sda_lan_automation_deployment.html#id_92081 - clearly states that uplinks CANNOT be moved. It also explains how to add a new uplink, so I though I could add a new uplink from the new stack member, and then remove one of the original uplinks. But there is no mention of how to remove an uplink.

Any thoughts on how this could be achieved?

Thanks

Re: Adding or changing the stack topology after LAN automation

balaji.bandi — Fri, 06 Aug 2021 21:26:28 GMT

Looks like Limitation :

4. Moving uplink to the newly added switch
Currently, it is not possible to move uplink from a stack that is already provisioned to the newly added switch to that stack. DDTS:

: CSCvk40550

https://www.cisco.com/c/en/us/support/docs/cloud-systems-management/dna-center/215336-lan-automation-step-by-step-deployment.html#anc43

Re: Adding or changing the stack topology after LAN automation

ianjgrant — Mon, 09 Aug 2021 07:31:19 GMT

Hi BB

The stated workaround is to run a new LAN automation process. How would this work in the real world? Yes, it would configure the new uplink, and bring it to a desirable state, but now I would have 3 active uplinks - in my scenario Te1/1/1, Te1/1/4, Te3/1/1. How would I get rid of the unwanted Te1/1/4 link?

The only option seems to be to manually remove the config at the Edge and Border CLI, but this goes against the idea of pushing all the config from DNAC.

Thanks

Ian

Re: Adding or changing the stack topology after LAN automation

balaji.bandi — Mon, 09 Aug 2021 08:33:29 GMT

The stated workaround is to run a new LAN automation process.  How would this work in the real world?

This means in real Live environment, you required downtime or maintenance window. to proceed as fresh kinda setup. ( or kinda fresh setup)

Sometime i agree even i have full of questions, we so called zero touch ( never seen this worked Fully as it was claimed, it required some network engineer intervention some wherre other).

Re: Adding or changing the stack topology after LAN automation

ianjgrant — Mon, 09 Aug 2021 10:29:22 GMT

Thanks BB.

With a bit of luck, a fixed release of DNAC will be available before I have to actually deal with it..