A multi-chassis configuration (i.e., vPC domain, MLAG, MCLAG, etc.) can be used to attach a hypervisor host to a pair of VXLAN-enabled switches. For example, a vPC consists of two vPC peer switches connected by a vPC peer link. A vPC domain is formed by the two switches; one switch is primary and the other is secondary. A switch can only be part of one vPC domain, and only two switches can make up a vPC domain.
A vPC allows links that are physically connected to two different switches to appear as a single port channel to a third device, which can be another switch or a server that supports Link Aggregation Control Protocol (LACP) as defined in IEEE 802.1AX, 802.1aq, and 802.3ad. With vPC deployment, the loopback interface that is acting as the source-interface for the VTEP will use the secondary IP address to function as the anycast IP address if the hypervisor host is dual-attached through the vPC. When a host is single-attached (orphan port), the VXLAN-encapsulated traffic will be sent using the loopback’s primary address. |