Terminology
Luigi
Luigi is a network operator that helps manage different network plugins such as whereabouts, SR-IOV, hostconfigs, and Multus.
NetworkAttachDefinitions
NetworkAttachDefinitions (net-attach-def) are objects that describe the network being created/defined to be available in the cluster. This can be of the type IPvlan, Macvlan, and SR-IOV.
Multus
Multus is a container network interface (CNI) plugin for Kubernetes that enables attaching multiple network interfaces to pods. Typically, in Kubernetes each pod only has one network interface (apart from a loopback). With Multus you can create a multi-homed pod that has multiple interfaces. This is accomplished by Multus acting as a "meta-plugin", a CNI plugin that can call multiple other CNI plugins. https://github.com/intel/multus-cni
Whereabouts
Whereabouts is an IP Address Management (IPAM) CNI plugin that assigns IP addresses cluster-wide. To track which IP addresses are in use between nodes, Whereabouts uses etcd or a Kubernetes Custom Resource as a backend. https://github.com/k8snetworkplumbingwg/whereabouts
Macvlan
Macvlan is a network driver/CNI that assigns a MAC address to each container’s virtual network interface, making it appear to be a physical network interface directly connected to the physical network. https://docs.docker.com/network/macvlan/
IPvlan
IPvlan is very similar to Macvlan, with an important difference. IPvlan does not assign unique MAC addresses to created sub-interfaces. All sub-interfaces share the parent's interface MAC address, but use distinct IP addresses.
IPvlan has two modes of operation. Only one of the two modes can be selected on a single parent interface. All sub-interfaces operate in the selected mode.
IPvlan L2 or Layer 2 mode is analogue to the Macvlan bridge mode.
Parent interface acts as a switch between the sub-interfaces and the parent interface. All VMs or containers connected to the same parent IPvlan interface and in the same subnet can communicate with each other directly through the parent interface. Traffic destined to other subnets is sent out through the parent interface to default gateway (a physical router). IPvlan in L2 mode distributes broadcasts/multicasts to all sub-interfaces
IPvlan L3 mode acts as a Layer 3 device (router) between the sub-interfaces and parent interface.
IPvlan L3 mode routes the packets between all sub-interfaces, thus providing full Layer 3 connectivity. Each sub-interface has to be configured with a different subnet, i.e. you cannot configure 10.10.40.0/24 on both interfaces.
Broadcasts are limited to a Layer 2 domain, so they cannot pass from one sub-interface to another. IPvlan L3 mode does not support multicast.
IPvlan L3 mode does not support routing protocols, so it cannot notify the physical network router of the subnets it connects to. You need to configure static routes on the physical router pointing to the Host’s physical interface for all subnets on the sub-interfaces.
SRIOV
The SR-IOV network plugin is Kubernetes CNI plugin for discovering and advertising SR-IOV virtual functions (VFs) available on a Kubernetes host based on confimap to deploy pods with high performance NICs.