Recabling APIC to a different pair of leaf switches in the same pod.

[ecsnnsls]

Hello experts,

I have a requirement where I need to recable two out of five APICs from one leaf switch pair to another. This is a single pod.

Should I decommission the APICs before changing it to a different leaf switch pair and then recommission them after connecting it to the new switch pair?

(or)

do I just shift the cables and the APIC re-establishes the cluster connectivity?

I am leaning more towards the latter because I can move one cable at a time so I really don't lose cluster connectivity, also since this is a single pod, there's no real requirement to recommission the APICs.

Thanks in advance.

[Robert Burns]

The safest procedure is to:
1. Make sure the Cluster is fully fit, export backup config to remote location (ensure you know all the answers for the APIC Setup Process (Infra VLAN, Subnet Info, GPO etc as you'll need this later)
2. Decommission the APIC (must be done from another other APIC than the one you wish to decomm).
3. Once completed and cluster showing fully fit, jump on CLI of that APIC and wipe it
          acidiag touch clean
     acidiag touch setup
     acidiag reboot
4. Once APIC starts to reboot (POST screen loads up) Power down the APIC completely (from IMC)
5. Move APIC fabric links to new leaf switch.
6. Power Up APIC
7. Run through Setup dialogue to re-join the cluster
8. Be Patient while everything syncs back up
9. Repeat Step 8.
Robert

[RedNectar]

Hi @ecsnnsls ,

Let me start by saying @Robert Burns has way more knowledge about this than I do, so I'm reluctant to advise otherwise, especially since I've never had to deal with more than 3 active APICs

However, I THINK you'd be pretty safe if you follow these steps, given that you can carry out the process with a maximum of one link down at any time.

1. Make sure the cluster is showing Fully Fit before you begin
2. Determine which of the links of the first APIC you are moving is the active link*
3. Move the active link to it's new location
4. Make sure the cluster is showing Fully Fit before you continue
5. Move the other link on the same APIC to it's new location
6. Repeat for the other APIC

---

* To determine active link

apic1# cat /proc/net/bonding/bond0 | grep Active
Currently Active Slave: eth2-1
apic1# acidiag run lldptool in eth2-1 | egrep -A1 "Port Description"
Port Description TLV
        topology/pod-1/paths-1201/pathep-[eth1/1]

[brlehigh]

I've moved a single APIC to a new leaf switch pair in the past.  I had to power the APIC down to relocate it, connected it to the new switches and powered it back up.  Everything worked fine.
I will say that I was left with a cosmetic issue when viewing the topology in the GUI where it showed the APIC still being connected to the previous leaf switches in addition to the new leaf switches.
I ended up engaging TAC to clean it up.