Hi,I have an Exchange server on hyper v. I have a virtual braodcom nic onboard on dell 2950. it is connected to dmz via cisco switch and cisco pix to internet. However every 2 or so hours i cannot get to port 25 from the internet thru the pic to the exchange server. i can telnet exchange server locally on port 25. it seems the pix closes the communication on this port but i dont know why or maybe its a problem with the catalyst cisco switch the card is connected to.The fix is to disable and enable the card and mail starts flowing in agian from the internet. But a couple of hours later and it closes again. I have disabled most options at this stage on the nicCan anybody help?ThanksCeltic

hi,can you check your connectivit with ; https://www.testexchangeconnectivity.com/and run ExBPA for healthy check.and if you can do use exchange server directly connected to internet for a few hours and check status. maybe there can be a problem on your NIC.regards,Mumin CICEK | Exchange - MVP | www.cozumpark.com | www.mumincicek.com

Hi,Please check whether the below article can help you:http://support.microsoft.com/kb/295725ThanksAllen