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58 Using MLAG in Dell Networking N-Series Switches | version 1.5

MLAG interfaces and non-redundant ports cannot be members of the same VLAN. That is, a VLAN may

contain MLAG interfaces or a VLAN may contain non-redundant ports, but not both.

Note: Solution 1 can run in an MSTP or RSTP-PV environment. Remove STP from the extra link to keep

the peer link unblocked.

Solution 2

The second solution, as shown in Figure 40, is to configure one or more MLAG partner switches between the

MLAG peers and the devices that require a single link. The single-homed devices (A, B, C, and D) can then

pass traffic across the MLAG domain.

MLAG

MLAG peer

Peer-Link

MLAG peer

Partner Y

Partner Z

Connecting single-homed

devices to Partner devices

already configured for MLAG

Device A Device C

Device B Device D

Solution 2 - Connecting devices to a partner switch

Solution 3

A third solution, as shown in Figure 41, is to multi-home the partner device, thereby creating an MLAG. Add

one or more cables to the device, creating a LAG with half the cables going to each MLAG peer attaining the

redundant multi-path advantage. To take advantage of MLAG, a device must attach to a minimum of two

partner devices.

MLAG

MLAG peer

Peer-Link

MLAG peer

Partner A

Partner B

Solution 3 – Multi-homed, Multi-switch LAG (MLAG)

The primary purpose of this guide is to explain the MLAG method (solution 3). Find a complete explanation

including N-Series switch configurations for this topology in the Single-Tier MLAG Example on page 12

. To

configure link aggregation for servers, storage or other devices, consult the User Guides for the NICs being

used in those devices.