Yes FEX will fetch the image from its parent switch and it does not matter where it was connected before. Think about RMA process if any FEX fails and you get and repalcement unit from Cisco. You do not know where it was connected before and what image it had.
Here is sequence of events happens when you connect any FEX to N5K or N7K
-Fabric extender is discovered by switch using an L2 Satellite Discover Protocol (SDP) that is run on the uplink port of fabric extender
-NX5K checks software image compatibility, assign an IP address and upgrade the fabric extender if necessary
-N5K pushes programming data to Fabric Extender
-Satellite Control Protocol (SCP) used to manage the running state of the line card
Introduction This article will help you understand the steps on how to
download the UCS licenses from the Cisco Systems website and then
installing it on the UCS. The redacted (blue lines) just covers up
certain numbers for privacy please do not take them...
Introduction This article will help you understand and educate the
customer on how to clear their "expired licenses"
(license-graceperiod-expired) from their UCS-M. If a customer just
purchased a license and needs a step by step guide on how to download
Introduction Prepositioning is a powerful tools on the WAAS platform but
it is not always easy to figure out why your jobs are failing when
trying to retrieve the files.Here is a method that should help you to
figure out the reason why they are not succes...