Dell N3200-ON Networking N-Series Switches User Guide version 6.8.0 - Page 1059

Multi-Switch LAG (MLAG) NOTE: This feature is not available on the Dell Networking N1108EP-ON, N1500 Series switch. Overview In a typical Layer-2 network, the Spanning Tree Protocol (STP) is deployed to avoid packet storms due to loops in the network. To perform this function, STP sets ports into either a forwarding state or a blocking state. Ports in the blocking state do not carry traffic. In the case of a topology change, STP reconverges to a new loop-free network and updates the port states. STP is relatively successful mitigating packet storms in the network, but redundant links in the network are blocked from carrying traffic by the spanning tree protocol. In some network deployments, redundant links between two switches are bundled together in a Link Aggregation Group (LAG) and appear as a single link in the spanning tree topology. The advantage is that all LAG member links can be in the forwarding state and a link failure can be recovered in milliseconds. This allows the bandwidth on the redundant links to be utilized. However, LAGs are limited to connecting multiple links between two partner switches, which leaves the switch as a single point of failure in the topology. Dell Networking MLAG extends the LAG bandwidth advantage across multiple Dell Networking N-Series switches connected to a LAG partner device. The LAG partner device is unaware that it is connected over a LAG to two peer Dell Networking N-Series switches; instead, the two switches appear as a single switch with a single MAC address to the partner. All links can carry data traffic across a physically diverse topology and in the case of a link or switch failure, traffic can continue to flow with minimal disruption. Link Aggregation 1059