Peter, thanks again for the great info. I already check the 3 ISA logs that i have namely:packet filters, firewall and proxy service logs, however I still can't find the NATted IP. Where in particular ISA logs can I find the particular NATd IP of my internal IPs? One more thing, I am trying to open my ISA summary logs but i cannot open it because its extension name is .ILS, how can I open it?thanks and hope you can help me...