DELL N3000 User Manual

Configuring Link Aggregation

MLAG is intended to support higher bandwidth utilization in scenarios 

where a redundant L2 network is desired. In such scenarios the effects of STP 

on link utilization are profound. Large percentages of links do not carry data 

because they are blocked and only a single path through the network carries 

traffic.

MLAG reduces some of the bandwidth shortcomings of STP in an L2 

network. It provides a reduced convergence period when a port-channel link 

goes down and provides more bandwidth because all links can forward traffic. 

In the figure below, if SW1 and SW2 form an MLAG with SW3 and SW4, 

none of the links are blocked, which means traffic can flow over both links 

from SW4 through to SW1 and SW2 over both links from SW1 and SW2 to 

SW3.

× 

Traffic does not flow
through SW2 due to 
spanning tree blocking 
the SW2/SW3 link.

SW4

SW3

SW1

SW2