AB Ethernet issue

Has anyone used an ethernet analyzer on an AB system to determine where/what an occasional error might be?

Experiencing sporadic errors on a mutiple IP address system that cannot be taken down to randomly replace cables or switches.

Hoping to "narrow it down" before digging into it.

I use fluke etherscope for this. Be prepared to pay 6-12K depending on options.

You can find places online to rent them also for like a week at the time if you don't want to buy.

Link http://www.flukenetworks.com/enterp...esting/EtherScope-Series-II-Network-Assistant