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

2 Caveats

Following are some of the requirements when implementing MLAGs:

• All MLAG peers must be the same switch series. Therefore, all peers of N2000 Series switches are

also N2000 Series switches, peers of N3000 Series switches are also N3000 Series switches, and so

on.

• Peer devices must use the same expansion module type if ports from the expansion module are to be

part of the MLAG interface.

• Neither of the two switches used as MLAG peers may be stacked with other switches.

• The peer link must have a native VLAN configured.

See the switch User Guide

for additional information.

2.1 Spanning Tree Protocol

Be sure all devices have the appropriate configuration regarding the Spanning Tree Protocol used, including

the MLAG peer link. Examples in this paper include RSTP, RSTP-PV and MSTP. The RSTP-PV protocol

provides a high degree of compatibility with Cisco’s RPVSTP+. MLAG supports MSTP as well, but RSTP-PV

compatibility requires the recently released DNOS 6.3.

2.2 Consistency of MLAG Peers

As mentioned above, the two switches used as MLAG peers, as well as any expansion modules, must match.

There are also six areas in the software configuration that must receive special attention to ensure they

contain identical information prior to enabling the MLAG (see Figure 3).

MLAG peer

peer

link

MLAG peer

Link Aggregation

MLAG Port-channels

Interfaces

VLANs

Firmware