Question : Problem: How can I properly analyze a network, PCs, routers, switches and servers to detect the cause of slowdown

My company is experiencing an odd problem. At 12:00pm EST every day the bandwidth nears 0 and all attempts at tracing network connections and bandwidth usage end with several  IP address distributors
so on a connection by connection or type of traffic basis there is no way to pinpoint specific software or even whether or not it comes from a server or workstation. Thus far the problem has been highly elusive.

Does anyone know of any tools that might help diagnose the problem from the workstation and server side?
Is it possible the problem may be introduced from/through a router, switch or printer ?
Zone Labs suggests a tool called Net Essentials by Tamosoft which allows a perpetual netstat. I was just wondering if there was maybe a special tool out there someone could recommend  or if anyone else has had a similar experience like this. The slowdown happens for about 30-60minutes each day.
Thus far this one has all the network people in my company stumped

Any help would be appreciated

Answer : Problem: How can I properly analyze a network, PCs, routers, switches and servers to detect the cause of slowdown

Hi,

You should use protocol analyzer to diagnose for possible broadcast storms. Wireshark is one nice option for such bandwidth related problems.

www.wireshark.org

Incase you are new to wireshark, then

wiki.wireshark.org

Also I recommend the below steps;

1- Turn automatic updates of any sort OFF on your desktops and servers.
2- Check if your Anti-Virus have latest virus definitions and each machine is scanned for any virus.
3- Check all machines/servers for spywares, adwares and malwares.