Implementation of CAS Array
Hi, We have three exchange servers 2010 on which all the three roles (CAS/HT/MBX) are installed. This servers are in DAG and within site only.
Now we are planning to install CAS Array in existing environment for fault tolerance of client connections.
Can someone guide what would be the prerequisites and changes need to be done in existing organization.
Now we are planning to install CAS Array in existing environment for fault tolerance of client connections.
Can someone guide what would be the prerequisites and changes need to be done in existing organization.
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Thanks for links...Our servers are in DAG that means Failover Cluster Service is installed.
Do NLB & FCS are supported simultaneously. If not, what is the alternative option to implement CAS Array in our environment.
Do NLB & FCS are supported simultaneously. If not, what is the alternative option to implement CAS Array in our environment.
Microsoft will not recommend for using NLB and cluster in same system,
If you have around 1000 user than follow below
first need to create CAS array, let ex. acasarry.mylab.local, then create DNS record for acasarray,
like:
acasarray = A record (Primary Mail server IP)
acasarray = A record (secondary Mail server IP)
DNS server user round robin functionality and load balance b/w to IP for acasarray
# one of my client using same for 5000 user
If you have around 1000 user than follow below
first need to create CAS array, let ex. acasarry.mylab.local, then create DNS record for acasarray,
like:
acasarray = A record (Primary Mail server IP)
acasarray = A record (secondary Mail server IP)
DNS server user round robin functionality and load balance b/w to IP for acasarray
# one of my client using same for 5000 user
ASKER
Ok..In our current environment, CAS & MBX role installed on same server, so we can't install NLB on same server, right?
Do we need to install separate CAS servers.
Do we need to install separate CAS servers.
FCS & NLB should not be mixed, its an unsupported scenario.
If you still want to try then you can use multiple NIC's each for FCS & NLB.
Otherwise go for Hardware load balancer
Or if may use ISA/TMG for load balance & have your CAS array point to it.
If you still want to try then you can use multiple NIC's each for FCS & NLB.
Otherwise go for Hardware load balancer
Or if may use ISA/TMG for load balance & have your CAS array point to it.
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That means either we have to purchase hardware load balancer or Separate CAS server for NLB, right?
Yeah, You are right.
If you can buy hardware load balancer is good otherwise use DNS round robin, it will also work
no need to install separate CAS on other server.
no need to install separate CAS on other server.
ASKER
Please elaborate how DNS round robin works for RPC client connections.
Does it remove requirement of NLB?
Does it remove requirement of NLB?
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Simon, Thanks for clarification.
We have small organization and hardware load balancer is expensive so we might choose second option to create additional CAS servers since we have additional licenses.
What else we have to consider before creating another CAS servers?
We have small organization and hardware load balancer is expensive so we might choose second option to create additional CAS servers since we have additional licenses.
What else we have to consider before creating another CAS servers?
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http://howtoexchange.wordpress.com/2009/12/16/configuring-client-access-array-for-exchange-2010-walkthrough/
http://blogs.technet.com/b/omers/archive/2010/10/11/microsoft-exchange-2010-cas-array-steps-and-recommendations.aspx
CAS array do not itself provide redundancy of CAS servers, you need to use either Hardware load balancer or Windows NLB.
http://blogs.technet.com/b/exchange/archive/2012/03/23/demystifying-the-cas-array-object-part-1.aspx