Configuration Guide

Table Of Contents
©2021 Extreme Networks, Inc. All rights reserved
October 2021
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17. SPB NNI SMLT – migrating existing SMLT
network to SPB
When migrating from a legacy SMLT network to SPBM, under certain circumstances, you may have to
change the MLT configuration as only one adjacency (port or MLT) is allowed between a pair of SPB
switches. Please see the drawings shown below illustrating the various options. Please note this section
does not apply to the ERS 4800 or ERS 5900 as SMLT is not supported on these products.
Please note the green links shown illustrate active links with IS-IS enabled where the link is
either a physical port or MLT bundle. Most of the topologies only really apply when migrating to
SPB with a SMLT cluster.
Figure 8: NNI - Triangle
In reference to switch C, it meets the
requirement of only one link between a pair of
SPB switches as it only has IS-IS enabled on
the port to switch A and on the MLT bundle to
switch B.
Figure 9: NNI - SMLT Triangle A
In reference to switch C, even though it has an
MLT provisioned, IS-IS is provisioned on the
physical ports to switch A and switch B. This
type of configuration may show up when
migrating to SPB where you may wish to not
remove the MLT configuration. Please note
that switch C can only be an ERS 8000 or VSP
9000.