Thanks for your response. But I want to use a different LAT on a firewall client to test purpose. I know that the LAT from the ISA server is use to determine if the firewall client have to intercept the request. But, in porxy 2.0, you can use a locallat.txt file, and the winsock client analyse the content of both files. Tom said in is excellent book that locallat.txt is usefull in ISA Server. But I can not arrive to use it and I waonder why ?