network looping

YaYangTeah used Ask the Experts™
Recenly we received call from our client said that network down and we visit onsite found that is looping .

She buy two unmanage switch try to connect by her self ,we found out she connect one of the cable back to the switch .

Actually they have are using HP 5130 as the core switch and all the access switch is HP/Aruba 2530.

I would like seek for expert advice ,what we can help them to avoid this problem occur again.
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Top Expert 2016
With managed switches one simply turns on spanning tree protocol and any port that is causing a loop will be shut down. Unmanaged switches mean one must pay special attention to both ends of the cable.
nociSoftware Engineer
Distinguished Expert 2018

You need STP [ Spanning Tree Protocol ]  (on managed) switches to PREVENT this.
And careful when setting up cabling...


my scenario is below:

HP 2530 <-- unmanaged switch 01<-- unmanaged switch02

What she loop the cable is on unmanage switch switch 02.From this scenario ,we turn on the spt on the switch port in HP 2530 will help ?
Software Engineer
Distinguished Expert 2018
No it is needed on all devices.  In your case the multiplication of any traffic (broadcast) is on  SW02  Your HP will not see BDPU's from one of it's other interfaces on the connected interface and thus will not detect the loop.

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial