my apologies for delay in Reply to you guys. Both of your input are very valid and solid to my knowledge. Question, can i test it out by connecting a same cat5 cable both ends to two switch ports on the same switch?
I discovered that it wasn't a loop the issue but instead dns error coming from the sdwan causing those multiple alerts to our NMS.
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Original Message:
Sent: Oct 14, 2025 04:38 AM
From: Herman Robers
Subject: Detect what's causing a loop in the network (Wired Devices or Wireless Device) in Cloud Central.
I saw a detection 2 weeks ago, where the actual problem at a customer was that STP was disabled, because if STP would have been enabled the loop should be terminated. Customer was seeing issues due to STP, so disabled it and created that loop problem.
So I can confirm that the loop detection in Central does work when STP is disabled. And what you will see as well is that High Broadcast because with a L2 loop you will get broadcast traffic being amplified and filling up the full bandwidth.
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Herman Robers
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If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.
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Original Message:
Sent: Oct 03, 2025 12:03 PM
From: SK90
Subject: Detect what's causing a loop in the network (Wired Devices or Wireless Device) in Cloud Central.
hi Muhittin,
I just noticed the stp is not enabled on the switch, also there are no redundant links on the Network because it's really flat. Unless you suggest another way.
here's a screenshots of the topology
Original Message:
Sent: Sep 30, 2025 05:45 PM
From: muhittin
Subject: Detect what's causing a loop in the network (Wired Devices or Wireless Device) in Cloud Central.
Hello,
Run the following commands and record the outputs:
show log -r | include loop-stp-bpdu-topology
show spanning-tree
show spanning-tree detail
show interfaces 1-x counters
show mac-address
Ports that increase broadcast counters and ports that enter a blocking/listening loop in STP are suspicious.
MAC flapping (the same MAC appearing on different ports in a short period) is an indication of a loop.
RSTP/MSTP - Edge - BPDU Guard provides protection when used.
conf t
spanning-tree
spanning-tree 1-x admin-edge-port
spanning-tree 1-x bpdu-protection - protect the port if BPDU arrives at the edge port
exit
write memory
The following commands for Loop-Protect provide protection in case a loop occurs:
conf t
loop-protect - enable globally
loop-protect 1-x - apply to edge ports
loop-protect action send-disable - temporarily disable the port if a loop is detected
loop-protect transmit-interval 2 - Probe every 2 seconds
loop-protect re-enable-timer 30 - Attempt to automatically reopen after 30 seconds
loop-protect trap - Generate syslog/snmp trap
exit
write memory
I hope these tips are useful. Please share your positive/negative feedback.