Mellanox VMS reference guide, offers a set of guidelines for a standard layer 3 based VMS and a standard layer 2 based VMS. Naturally, network designers may find it necessary to apply some topology modifications to better suit their needs and are eligible to choose either the layer 2 variant or the layer 3 variant of the VMS, according to their professional preference and network needs.
L3 VMS is based on IP and OSPF configuration. The IP network topology is discovered via the OSPF routing protocol that is enabled on all ToRs and aggregation devices in the network. OSPF routers exchange link status messages with their physical neighbors in order to establish the same network topology for all routers in the network.
L2 VMS is based on Ethernet configuration and MSTP. The distribution leans on the MSTP protocol, where the number of MSTP instances is equal (or greater) to the number of spines in the VMS and each spine is a root bridge of a different MSTP instance. In such topology, load balancing is achieved between the different MSTP instances and triggered by the server applications. Each instance creates a different tree to a different set of VLANs. This way, a part of the VLANs will pass from one spine, another part of the VLANs will pass from another spine and so on. Note that if the number of VLANs in your network is smaller than the number of
spines, the utilization of the VMS will not be efficient. For example, in case there is only one VLAN, only one spine can be used. The rest of the spines will be alternative routes for the MSTP tree.
Click here for to check the Mellanox VMS reference guide, available now with configuration guidance and examples for L2 VMS: