I've never done a clustered install but have built many exchange boxes from the ground up. Currently their are two servers in a 2 node single copy cluster with another handling HT and CAS roles. The windows cluster and exchange cluster installs went by without a glitch. i've added all the host and cluster hosts and IP's to dns. the domain controllers and exchange servers can ping eachother and get a reply but externally pinging the exchange server or cluster virtual host doesnt yield a reply. Internally getting to OWA which is enabled by default doesnt work, and i tried using outlook express internally on one of the domain controllers didnt work either. I also have blackberry enterprise server installed but i doubt if thats a problem. where could this communication problem be sitting? Also this setup is not proprietery, its being routed behind a unix sendmail system. any insight of things to check will truely help.

i figured out the ping problem,. thats fixed but i still cannot communicate with exchange or resolve mailbox names.

Do you mean you install Mailbox Client and Hub transport server role on same box in 2 cluster node? If yes, as I know on mailbox server role can be support cluster . Please reference this article http://technet.microsoft.com/en-us/library/bb125149.aspx Only the Mailbox server role can be installed in a cluster. No other WindowsServer roles can be installed on a computer that is part of a failover cluster.

I understand that the mailbox roles are the only supported services in a 2 node Active/Passive cluster. My question is, if you do not cluster the Hub Transport services on the 2 node cluster, will the Hub Transport roles work? The hub transport load balances by default and this would give some fault tolerance to the Hub Transport role without having to add additional servers to support this role (If it willwork in this manner, a real big If....) I have not tried it....... Has anyone else tried it? and if so, will Microsoft support this configuration.