Explain to a customer why an AI cluster has a primary CNI plus a separate second interface, and build the second path's software pieces (Multus, macvlan/ipvlan/host-device, cluster-wide IPAM, MTU) on hardware you already have.

1. 1.1 The Kubernetes network model and where a second CNI fitsEight nodes, thirty days, one interfaceU
2. 1.2 Primary CNI choices: Calico and CiliumThe kernel that said noAn
3. 1.3 MTU budgeting across switch, host PF and podThree numbers and one screenshotAp
4. 1.4 Multus and the NetworkAttachmentDefinitionThe perfect manifestAp
5. 1.5 macvlan, ipvlan, host-device and cluster-wide IPAMWhose ticket it actually wasAn
6. Checkpoint