Hello Jim, I'm not sure what is the problem here. From my previous email I suspect that after installing the DNS service onto the ISA Servers that cause the problem of intermittent connection problem. I have read the dns documentation,but still do not understand on how should I proceed. The ISA server that we have only got one NIC card, two ports with the same IP Address.I'm using the Compaq Teaming card. thank you & regards.