I was wondering how the following situation can be handle. Is it possible to use a ASA if internet is established by a PPPoa (username/password required) ADSL modem? Let say a ASA is placed between a Exchange server (in a DMZ) and a PPPoA ADSL Router. Does the build-in NAT (ADSL Router) causes trouble? If an email must have access to the Exchange server then first the ADSL router must let it through (in most cases by configuring NAT port 25) before it can get to the ASA....sounds like a recipe for trouble..
* So, is it possible to use a ASA combined with a PPPoA (username/password required) internet line?