I am trying to install NLB on Exchange 2010 CAS servers, and i follow this article http://exchangeserverpro.com/how-to-install-an-exchange-server-2010-client-access-server-array After finishing everything only the 2 CAS servers can connect with NLB cluster name but the other servers and clients can not connect with the NLB cluster name i have two CAS servers with 2 NIC the 1st server configuration Public 192.168.2.27 mask 255.255.255.0 with gateway and DNS NLB 192.168.2.31 mask 255.255.255.0 the 2st server configuration Public 192.168.2.28 mask 255.255.255.0 with gateway and DNS NLB 192.168.2.32 mask 255.255.255.0 the 2 Public NIC connected to network switch and the 2 NLB is connected to each others

all 4 nics need to be on the "public" network... No cross cable or seprate network.. this is not like a heartbeat in a cluster

Dear Katiyar, Agree with lafontma, please refer the topic : http://exchangeserverinfo.com/2008/03/20/network-load-balance-for-hub--cas--exchange-2007.aspx

Dear Saalaah, Agree with lafontma, there is no cross cable with NLB just connect all the servers to your public network. Please Check the following link: Uncovering the new RPC Client Access service included with Exchange 2010. http://www.msexchange.org/articles_tutorials/exchange-server-2007/planning-architecture/uncovering-new-rpc-client-access-service-exchange-2010-part1.html