DNS Round Robin on CAS Array

Status
Not open for further replies.
P

privatep

Hi,

I have 1 2003 exchange server and will transition to 2 exchange 2010 servers environment.

I installed 2 Exchange 2010 servers and have implemented DAG and CAS Array. The cas array fqdn is casarray.org.com and created 2 A records pointing to the 2 exchange servers (svexc01 and svexc02) Both servers running CAS, HUB and MBX

casarray.org.com to match ip addr of svexc01

casarray.org.com to match ip addr of svexc02

I've test HA on DAG and CAS array and works fine.

I would like to know if DNS round robin is supported with 2 Exchange server 2010 environment running DAG and CAS Array. WLB is NOT installed on these server

Cheers
 
L

lAdK

yes DNS round robin is supported well it is simply not related to exchange, you are practically relying on DNS to send users randomly to server 1 or 2

what you should know however is that if one of the servers goes down you will need to delete in the DNS the entry corresponding to its IP or 1/2 users will stay disconnected

a small tip lower the TTL for these record

lAdK
blog | twitter
 
S

Sembee [MVP]

Round Robin doesn't really help with a CAS Array. If one of the servers goes down, then the DNS will continue to send clients to that host because has no awareness that the server is down. I don't see how you say that it works fine. You really should be using at least WNLB so that there is some server availability awareness, or you are going to need to have a process to remove the down host from DNS - which could take some time depending on when the failure occurs.

Is there any reason why you aren't using at least WNLB?

Simon.

Simon Butler, Exchange MVP
Blog | Exchange Resources
 
P

privatep

Hi, Simon

So I could use a 3rd server with WNLB and load balance the CAS array?

I was reading somewhere that you cant install WNLB on any DAG members seeing I only have 2 servers running DAG and CAS array.

cheers
 
T

TWHarrington

You are correct that you cannot install WNLB on a DAG server since it cannot coexist with Windows Failover Clustering. As stated above, DNS roundrobin is not recommended for a CAS Array. To do this right and provide true HA for all roles, you need to split the CAS role off of your DAG/MB servers. So you need two new servers, move the CAS role onto those new servers with WNLB installed and configured. If you want to stick with the 2 Exch server solution, the proper way is to load balance with a hardware load balancer. Here is a link that explains the scenaios:

http://www.shudnow.net/2010/03/17/exchange-2010-rtm-high-availability-load-balancing-options/

 
Status
Not open for further replies.
Thread starter Similar threads Forum Replies Date
T Exchange 2003, NDR, DNS problems Exchange Server Administration 3
B Promoting and demoting dns w/ exchange 2007 sp2 environment Exchange Server Administration 1
R Dynamic DNS update requirement for Exchange 2010 (SP1 RU1) on server 2008 r2 Exchange Server Administration 8
S Cluster Name failed to update the DNS record Exchange Server Administration 2
J Missing HUB DNS record results in mail piling in queue, no failover? Exchange Server Administration 2
F OWA internal and external address is trying to resolve on an external DNS server on the internet Using Outlook 2
S Exchange 2003 coexistence with Exchange 2010 (Edge, OWA, Certificate, DNS considerations) Exchange Server Administration 3
B Transition for OA/OWA/AS and DNS Exchange Server Administration 3
S Active Passive DAG seperate DNS namespace Exchange Server Administration 7
S DNS query failed error in exchnage 2010 only while sending email to hotmail.com Exchange Server Administration 7
T 451 4.4 dns query failed on exchange 2010 hub transport server Exchange Server Administration 1
S internal dns name on certificate Exchange Server Administration 1
D DNS Query Failed Exchange Server Administration 14
P External DNS Question; 2003-2010 Migration Exchange Server Administration 5
B DNS Settings for Exchange 2010 - a slightly different scenario Exchange Server Administration 3
B Configuring DNS when migrating to Exchange 2010 from Exchange 2003 Exchange Server Administration 3
P How Do I get this to work? DNS/Exchange question Exchange Server Administration 12
A Exchange 2010 DAG with non Microsoft DNS (and non-dynamic updates) Exchange Server Administration 4
D 451 4.4.0 DNS Query Failed. Exchange Server Administration 3
M How to Break / Stop Autodiscover Outlook 2007 to Exchange 2003 using DNS Using Outlook 3
K Exchange 2010 only allows me to setup Outlook accounts when using it as my DNS servers Exchange Server Administration 11
S Exchange Server 2010 Autodiscover Public DNS Record Exchange Server Administration 6
A Need help setting up dns for exchange 2010 Exchange Server Administration 1
M 451 4.4.0 DNS query failed. The error was: SMTPSEND.DNS.InvalidData; DNS returned an invalid respons Exchange Server Administration 3
S You have no reverse DNS entry. Using Outlook 2
R Assign Categories "Round Robin" style but in a shared mailbox but on specific emails only Outlook VBA and Custom Forms 8
Similar threads


























Top