Exchange 2013 - NLB on VMware

Hi guys,

Quick question if you don't mind, i'm setting up an Exchange 2013 Environment at the moment and we are wanting to set up NLB for the CAS servers. However these will be split across 2 sites, I was just wondering would I need to add the static ARP entry on both site switches? We have Juniper switches in each site but also Cisco in 1 of the sites, the Cisco is directly connected to our juniper switch. Thanks so much for your help
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Jakob DigranesSenior ConsultantCommented:
do you have split roles? CAS on some serves and MBX on others?
Windows NLB cannot be used together with DAG.

Exchange 2013 is recommended as multi-role servers, with both CAS and MBX collocated. Then you can use DNS load balancing instead
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
If you are using Multicast NLB as recommended, *YOU MUST* allocate static ARP entries on ALL the physical Cisco Switches, you would expect to find that traffic, not just the switches, that the ESXi hosts, are connected to, but everything inbetween, and all trunk or uplink ports.
Jakob DigranesSenior ConsultantCommented:
Active Protection takes the fight to cryptojacking

While there were several headline-grabbing ransomware attacks during in 2017, another big threat started appearing at the same time that didn’t get the same coverage – illicit cryptomining.

TerellionAuthor Commented:
Yep got 2 CAS Servers and 2 MBX servers, CAS-01 is on one site and CAS-02 is on another. So would I have to set the static ARP entries on every single site switch that users would have Outlook on? That is 17 sites in total, most having 2 or 3 stacks of switches also...
Simon Butler (Sembee)ConsultantCommented:
The Exchange product team don't recommend the use of WNLB. Pretty good reasons as well, because it sucks.
You would have been better of saving the money on the Exchange licences for the separate CAS role and putting it towards a load balancer.

What kind of load are we talking about? If it is a relatively small site then Kemp have a free load balancer option which will be a lot more reliable than WNLB.

You have said that you are going across two sites - these are two separate AD sites? Load balancing across sites doesn't always work very well. The best method there is DNS entry changes because otherwise you are going to get in to a routing mess.

Jakob DigranesSenior ConsultantCommented:
One vote for Simon here ...
collocate servers.
By the way, started the day by testing DNS round robin load balancing, and DAG across different data sites here. As long as DNS are set correctly with TTL and all entries, the client was stuck at Trying to connect for up to a couple of minutes until it automagically was connected to server in 2nd data site.

if you should go with HW LB, you'd need 2 aswell; for redundancy
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
So would I have to set the static ARP entries on every single site switch that users would have Outlook on? That is 17 sites in total, most having 2 or 3 stacks of switches also...

That is correct, and make sure you test, and check the Multicast Converges.

get your network diagrams out, and work out which ports, and where the multicast traffic will go...

You could also use Zen, it's free also!

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
TerellionAuthor Commented:
Thanks guys, I managed to get away with adding the static ARP entries on the Juniper stacks that our ESX hosts are connected to and then just set up routing for the NLB subnet and all is good! thanks so much :)
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.