Aruba 2530-24G Switch diagnostics

[Kresho]

Dears, 

I have star configuration network in production plant with 12 Aruba 2530-24G J9776A switches. Network contains Siemens PLC's and PC's which comunicate between each other (earlier these were 3Com switches and we decided to replace all of them with Aruba due to cooling fan failures in 3Com).

We are facing comunication fault approx.. once a week which is being caused by "looks like" switch freezing - always same 3 switches has to be rebooted and communication returns back to normal. In log file we found same repeated warnings: "High collision or drop rate" and "Excessive broadcast detected on port 25".

We have replaced these swithes several times but same issue is coming back. this issue started to happen 2 years ago and since then it would dissapear for a few months on itself and come back.

I have very limited knowlege about networks and switches so i had several "specialized" companies to review our network configuration and nobody seams to know whats going on. 

Please share your thoughts if you had similat problems.

I can provide additional information about switches configuration and network topology if required just please specify which data is required. 

Thanks

[parnassus]

Provided that you network doesn't contain loops and it is based on a star topology...how is configured Spanning Tree across various switches? It looks like you're suffering from some sort of network instability (so concepts like spanning tree root, root-guard, loop-protect and bpdu-protection, edge ports should be investigated if they were applied on your network).