3Com 5500 SI - Switch - Stackable, Configuration Manual

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682 A
PPENDIX
D: 3C
OM
XRN
Figure 182 How XRN interacts with VLANs—Example 2
Legacy Aggregated
Links
Legacy aggregated links, will react in the normal way if a unit within the
Distributed Fabric fails, that is, all traffic will be redirected down the link(s) to the
unit that is still operating.
However, in Figure 183, if the interconnect fails, the aggregation is still a single
logical entity at the legacy Switch end, but it is now split over both units within the
Distributed Fabric. The legacy Switch is not aware that the aggregation has split
and will continue to send traffic over both links, resulting in data loss.
Hence the recommendation to use IEEE 802.3ad aggregated links, if possible, as
legacy aggregated links are not resilient to an Fabric Interconnect failure.
Figure 183 How XRN interacts with legacy aggregated links