Deployment Guide

12 VxRail Networking Guide with Dell EMC S4148-ON Switches | version 1.0
2.1.2 Dual-switch topology
This topology establishes network redundancy at both the link and the switch level. Failure of a single-switch
or network link does not cause an overall loss of communication.
In the dual-switch topology, each node connects to both switches in an active/standby capability. Refer to
Appendix C for detailed information. The two S4148-ON switches connect with either a VLT configuration or a
port channel configuration. VLT is preferred and is a Dell EMC Networking layer 2-multipathing technology,
which allows for running a loop-free layer 2 (L2) multipath network without any blocked ports. VLT
synchronizes layer 2-table information between the switches and makes the switches appear as one logical
unit.
Usually a server connects to the pair of VLT switches with a LACP LAG. However, LACP is not used with
VxRail nodes since the nodes are configured with a virtual switch with active and standby adapters. Other
non-VxRail devices can utilize LACP LAG to the pair of VLT switches, for an active/active L2 multipathing
scenario.
In a multi-switch environment, configure the ports used for inter-switch communication to carry IPv6 multicast
traffic for the VxRail management VLAN. Likewise, configure the ports to carry IPv4 traffic (unicast starting in
VxRail Release 4.5.0 and multicast in prior releases) between switches for the vSAN VLAN.
Example of a dual-switch topology