OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
page 10-1
10 Configuring Multi-chassis
Link Aggregation
The Multi-chassis Link Aggregation feature (MCLAG) provides resiliency at the edge of the network by
enabling dual homing of any standards-based edge switches to a pair of aggregation switches to provide a
Layer 2 multi-path infrastructure. MCLAG enables a device to form a logical link aggregation (LAG)
interface with two or more other devices, providing additional benefits over traditional LAG in terms of
node level redundancy, multi-homing support, and loop-free Layer 2 network.
MCLAG allows links that are physically connected to two different switches to appear as a single link
aggregation group to a third edge device. MCLAG provides this functionality without running Layer 2
loop-detection protocols, such as the Spanning Tree Protocol, between the edge and aggregation switches,
while still detecting data loop conditions, failure detection and convergence.
The following are some key points regarding MCLAG configuration:
•
MCLAG provides active/active dual homed connectivity to standards based Layer 2 edge devices.
There is no support for standby ports.
•
Internal automatic configuration will disable Spanning Tree functionality on MCLAG aggregate ports.
•
MCLAG peers are seen as one aggregated group to dual homed edge device(s).
•
MAC addresses learned on an MCLAG aggregate in one of the multi-chassis peers are also learned on
the other switch on the same MCLAG aggregate.
•
A loop or duplicate packet prevention mechanism is implemented so that non-unicast frames received
on the Virtual Fabric Link are not flooded out any local MCLAG ports
For more information on components of MCLAG, see