Take a look at http://www.isaserver.org for docs on how to do this. Keep in mind, you'll need to open TCP 80 to the BE server from the FE server and from the FE server to all DC/GC/DNS servers is might talk to unless you hard code the DSACCESS server list. Once you've done that, you may as well have followed the recommended solution which is: ExchangeBE--->ExchangeFE--->ISA Server_publishing_Exchange_FE server Al -----Original Message----- From: Pham Van Huong [mailto:pvhuong@xxxxxxxxxxxxx] Sent: Monday, March 22, 2004 8:12 PM To: [ExchangeList] Subject: [exchangelist] ISA & EXCHG_FrontEnd http://www.MSExchange.org/ Hi All, I's installed diagram belows EXCHG_BackEnd----ISA_in-----EXCHG_FrontEnd----ISA_out There's no problem with Exchange Backend, FrontEnd, and ISA_out. But, I couldn't open ports on ISA_in to allow EXCHG_FrontEnd to come in. I've try using IP Packet filter to create All Inbound for EXCHG_FrontEnd, but, nothing's better. How can i do with it now? Pls help me. Thanks, VH ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ Other Internet Software Marketing Sites: Leading Network Software Directory: http://www.serverfiles.com No.1 ISA Server Resource Site: http://www.isaserver.org Windows Security Resource Site: http://www.windowsecurity.com/ Network Security Library: http://www.secinf.net/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------