A multi-homed host device is a device that is connected to more than 1 leaf node in a fabric. A host device can create ethernet links to up to two (2) leaf nodes. These links are collectively known as an Ethernet Segment (ES). Each ES is identified by a unique 10-octet hexadecimal identifier known as an Ethernet Segment Identifier (ESI). This ESI is used by the leafs to identify that they are a part of the same ES.
Multi-homing enables maintenance of EVPN services in case of the following types of network failure:
Core Failure - Failure of link between the Leaf and Spine nodes of the Fabric.
Leaf Device Failure - Failure of a Leaf to which the host is connected.
Client Interface Failure - Failure of the link between the host and the Leaf to which the host is connected to.
Note
BGP EVPN Multi-homing is supported on the SLX 9150 and SLX 9250 platforms. It is not supported on the SLX 9540, SLX 9640, and SLX 9740 platforms.