Hi Everyone, I'm running Exchange Server 5.0 on WINNT 4.0 on my LAN. This is my question/issue. About once a week my network utilization report on my switch, shows a really high and steady network utilization occuring (incoming & outgoing traffic) on the port where my exchange server is connected. I installed a packet sniffer to capture the activity. This helped me find the culprit computer, which is not always the same. The only way I found to stop the excessive traffic is by rebooting that computer. This is my quick fix for now until I can decrypt the captured packets. The traffic communicates between ports 1042, 1050, 1056 and are using DCERPC protocol. Is this some type of message that keeps going into an endless loop? As anyone ever encountered this problem, if so how did you solve it? Does anyone know of other troubleshooting tools which can help me futher decrypt this traffic. Your help would be greatly appreciated and thanks in advanced, Carmine