Setup Guide

Layer 3 – Core Uplinks
Uplink A Uplink B
Layer 2 – ToR Switches
Port Channel
MC-LAG
Interconnect
Figure 16. ToR switches with MC-LAG interconnect
NOTE: Port location for the reliable high speed uplinks may change depending on switch vendor or model.
MC-LAG is a switch interconnection technology that joins a number of independent Top-of-Rack (ToR) switches into a single
virtual chassis. MC-LAG allows the link aggregation (LAG) port groups to span multiple chassis, enabling better resilience of the
LAG connection. Additionally, MC-LAG enables traffic going from switch to switch using the full bandwidth of the available
connection, without using spanning tree protocol (STP), which would disable some links to prevent loops.
MC-LAG is a general name for the technology, however certain vendors use their own proprietary terminology to define MC-
LAG connectivity.
Table 15. Vendor specific MC-LAG technology
Vendor Proprietary MC-LAG technology
Dell Virtual Link Trunking (VLT)
Cisco Virtual PortChannel (vPC)
Brocade Multi-Chassis Trunking (MCT)
NOTE: Refer to your vendor's documentation to determine their technology for MC-LAG.
MC-LAG connectivity requirements are:
● A minimum of two connection cables in parallel with a high speed reliable connection.
● Connections must be made through the high speed ports on the switch. Verify with your switch provider documentation
where the high speed ports are located on your switch.
● Use two cables that support connectivity between the high speed ports. For example 100Gbps Direct Attached Cables
(DAC) would be required to connect the MC-LAG ports together.
L2 Uplinks without MC-LAG
Using L2 (Ethernet level) uplinks without an MC-LAG connection to connect the ToR switches is an acceptable alternative to
MC-LAG for PowerStore deployments.
With a non-MC-LAG L2 connection you can port-channel the uplinks on each physical switch, which requires creating two port-
channels instead of one.
Switch and network requirements for deployments with ToR switches
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