Andres, The Cisco Road Map for the 5010 and 5020 doesn't include extending the current total (12) FEX capabities. The 5548 and 5596 will support more (16) per 55xxk, and with the 7K will support upto 32 FEX's. Documentation has been spotty on this subject, because the term 5k indicates that all 5000 series switches will support extended FEX's which is not the case only the 55xx will support more than 12 FEX. Maybe in the future the terminology for the 5k series should be term 5000 series and 5500 series Nexus, there are several differences and advancements between the two series.
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