We have an isolated network connected via an ISDN line to the a production environment. Within the isolated network there is a tree root (domain1.com) and child domain (child.domain1.com). There are no trusts to the production network. There is a Proxy 2.0 server available in the production network. We have configured an ISA proxy server (only) in the child.domain1.com domain, and within the routing we have setup a rule to look upstream to the Proxy 2.0 server in the production environment. This includes a domain2 production account in the configuration to use for authentication against the Proxy 2.0 server. There is a Protocol rule and a Site and Content rule configure to allow all for all users. The client machines are also configured to look at the ISA proxy server (port 8080). The error we are getting is when the browser is opened on the client machine, a log on box pops up, and when the domain2 production account details are entered the requested web site is presented. We are trying to get the configuration right so that this pop up does not appear. It seems as though the ISA server is not passing the domain2 account details to the upstream Proxy 2.0 server. I have run a Netmon, and the upstream Proxy 2.0 server is not getting the account it requires for authentication. Any ideas would be helpful. Thanks, Nick White