A game studio cabled each new ACI leaf management port to an out-of-band switch and did not uplink those leaves to any spine. The leaves never join the fabric. What is missing?
Select an answer to reveal the explanation.
Short Explanation
Out-of-band cabling is the office phone, not the road into the fabric. You gave each leaf a management cable and no uplink to a spine, so discovery has no fabric path to walk. A leaf-to-leaf ring or a vPC peer-link is not how an ACI leaf joins.
Full Explanation
A standard ACI fabric discovers a leaf across its fabric uplinks to the spines. The APICs attach to leaves, and the infra VLAN on those fabric links carries discovery. An out-of-band management cable gives operators a management path. It is not a fabric link, so the studio leaves never join when that is all they have. Cabling leaves to each other in a ring does not create the Clos. Leaves do not use leaf-to-leaf links as their fabric ports. The APICs belong on leaf ports, not on spines, and they do not discover leaves by proxy through an out-of-band management switch. A vPC peer-link is an NX-OS construct. ACI fabric discovery does not require one between leaves, and adding one would not make a spine accept a leaf that has no fabric uplink. Caveat: once the leaf does join, out-of-band management is still useful for reachability, and it remains separate from the infra VLAN on the fabric ports. Operational check: uplink each leaf to the spines, confirm the leaf discovers as a fabric node, and leave the out-of-band cable as management only.