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11 Using MLAG in Dell Networking N-Series Switches | version 1.5
3 Supported Topologies
MLAG topologies offer several options. They can be a single layer (one pair of MLAG peer switches) or two
layers (two pairs of MLAG peer switches). The peer link can have anywhere from one to eight active
interfaces to create the link. With these and other variables, there are dozens of ways to set up an MLAG.
Table 2 lists all supported topology options:
Parameters for an MLAG topology
Topological parameter
Supported options
MLAG domains per switch
1
Peer switches per MLAG domain
2
Interfaces per MLAG
2 to 8
Interfaces per peer link
1 to 8
MLAGs connecting to MLAG domain
Limited only by number of ports available
Layers
1 or 2
Note: Spanning tree is enabled by default on MLAG peer links. Do not disable spanning tree on 6.3.0.0 or
later releases. Use a redundant link between MLAG peer switches to support routed Layer-3 link failures.
Separate VLAN and MSTP instances are preferable in such situations. Please refer to N-series manuals for
more details at https://support.dell.com
Figure 4 shows a few examples of MLAG topologies that the MLAG feature supports. The red lines show the
peer links between the primary and secondary peer switches. The blue line in the bottom diagram shows
compatibility with virtual link trunking (VLT) and virtual port channel (vPC) in a layer 2 topology. VLT is a
technology similar to MLAG that is used with certain Dell switches like the S4810. vPC is a technology similar
to MLAG that is used with certain Cisco switches like the Nexus 5k and 7k. See the User Guide for the S4810
and other Dell switches that use VLT for guidance on implementing a vPC.
full mesh
1 partner switch
3 partner switches
VLTi
2 partner switches
MLAG and VLT
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MASTER
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full mesh
vPC
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full mesh
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Examples of MLAG topologies