I have an IBM AS400 located behind my ISA server that I have published to the internet so my remote users can telent in to the AS400. The setup works fine except that when a remote user looses internet connection for any reason the AS400 does not see that he is gone and his session must be ended manually so he can get in again. We use Network Address Translation on the ISA server to redirect a public address outside to a private one inside. When we remove the ISA server and use a CISCO router to do the NAT the AS400 does see the remotes when they drop and and automatically ends their session so they can get right back on. What is it that I need to open on the ISA server to let the AS400 see the remotes that have dropped?