DNS Load Balancing in Lync Server 2010

re: DNS Load Balancing in Lync Server 2010

Keith Hanna [msft] — Tue, 13 Nov 2012 13:52:56 GMT

Hi Stan,

there's no impact when using virtualisation from the high level perspective - the clients are still directed to a front end based on the load balancing method chosen (either DNS or HLB).

However one thing to be aware of, is when front end servers are sharing the same physical host and NIC, whilst you ay be directing traffic based on the target VM, it may be actually traversing a shared NIC. The only way to avoid this is to ensure that each VM has a dedicated NIC.

Keith

re: DNS Load Balancing in Lync Server 2010

Stan — Tue, 30 Oct 2012 15:26:56 GMT

How is the use of DNS-LB/HB effected when you virtualize LYNC 2010? Can you use HLB with a virtualized installation of LYNC?

re: DNS Load Balancing in Lync Server 2010

Keith Hanna [msft] — Mon, 17 Sep 2012 18:44:47 GMT

Hi Doug,

Round robin can play a part that is correct, however strictly speaking due to the random nature of the connection which the client chooses, enabling or disabling round robin on the server will have little impact.

You are correct in that a *Windows* client will select the first entry in the DNS response, however this is not how a *Lync* client behaves, rather it will take all the responses and randomly select from this for the first connection (and in response to unsuccessful connections).

Keith

re: DNS Load Balancing in Lync Server 2010

doug@webster — Mon, 17 Sep 2012 14:29:41 GMT

Sounds like round robin to me, if its a Windows Server serving the DNS records then it does this in a round robin style.

Also the windows client picks the first address returned, not a random address.

re: DNS Load Balancing in Lync Server 2010

Keith Hanna [msft] — Mon, 02 Jul 2012 15:34:38 GMT

Hi Richard,

Direct access is required for client access to all front end servers - not just for SIP, but also for conferencing. There is no way to 'hide' front end servers 'behind' a hardware load balancer.

upon first connection to a front end server the client will be directed to it's home server and will need a direct connection. The only exception to this is if the connection from the HLB is directed to the client's home server in the first instance.

Keith

re: DNS Load Balancing in Lync Server 2010

Richard Pasztor — Sat, 30 Jun 2012 16:20:50 GMT

How do you make sure the client connects to his home server, if all the Front End servers are behind a Hardware Load balancer, and -as far as I know- there is no such HWLoadbalancer-bypass to have direct connection between the client and the designated FE server?

re: DNS Load Balancing in Lync Server 2010

NextHop — Fri, 23 Mar 2012 15:50:07 GMT

Thanks Jonas!

Use can use the get-csuserpoolinfo cmdlet to show the view of the logical register based on the currently installed servers, but it will only give a 'true' reading if the pool is fully populated.

GW2691, OCS clients and servers do not understand DNS loadbalancing, therefore cannot receive the benefits of it. So whilst it will work, there is no logic in the event of a failure to tell the clients and/or server to connect to a different (available) front end in the pool.

Hope that helps

Keith

re: DNS Load Balancing in Lync Server 2010

gw2691 — Thu, 01 Mar 2012 16:36:37 GMT

I have and existing OCS installation and i have just set up Lync. OCS does not go through any load balancers. I am thinking of using DNS Load Balancing will it affect OCS users talking to Lync users or the migration of users to Lync?

re: DNS Load Balancing in Lync Server 2010

Jonas Mellquist — Fri, 03 Feb 2012 10:29:52 GMT

Hi Keith, this article is very well written. The Nexthop blog is an essential source of information when learning about Lync Server 2010 and the inner workings going on, but some articles are super hard to read, this one is not one of them, kudos!

A quick question - is it possible to view the current logical registrar sequence for a given user?

re: DNS Load Balancing in Lync Server 2010

Nisha — Fri, 16 Dec 2011 04:39:18 GMT

Hello friends,

Route53 is one of the service provided by Amazon.It can handle large volume of DNS queries.We have developed an User Interface for route53 services - DNS30 Professional Edition.Online Interface for this service is also available.

http://www.dns30.com/