Our envirment is going to have 2 ISA 2006 servers in front of CAS/HT, it was recomended to us to install the SAN cert that we are installing on the ISA boxes to also install them on the CAS/ht servers instead of installing our own internal cert on the CAS/HT. Just want some thoughts on pro's and cons on this idea.

Only ISA 2006 SP1 supports SAN, I assume you knew that already Per my knowledge, unified certificate would easier the administration In order ensure the communications between the ISA Server computer and the CAS server are properly secured, a server certificate is required to be installed on the CAS server. This certificate can be from a windows CA and does not need to be purchased. Yet, the root CA certificate of the CA that issued the server certificate on the CAS server must be installed on the ISA Server James Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com

Well, im not sure whats the question or doubt can you give a little more explanation...as i understand you are not doing anything wrong..CapecolMCSA - MCTS Exchange Server 2007