network looping

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.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Johnson, CD, MVPRetiredCommented:
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 EngineerCommented:
You need STP [ Spanning Tree Protocol ]  (on managed) switches to PREVENT this.
And careful when setting up cabling...
YaYangTeahAuthor Commented:
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 ?
nociSoftware EngineerCommented:
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.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Switches / Hubs

From novice to tech pro — start learning today.