Can be many things... UTP cable that is operating in the margin, power budget on the switch that may be insufficient at one point, and sufficient at another point, switch port types 10/100 10/100/1000 100/1000 smart rate, switch configuration, etc and the switch types, power negotiation (or not), LLDP-MED, ..
Hard to tell what it is, from what you describe.
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
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