Re: How does Network Load Balancer deal with Single affinity?

"Yash" <> wrote in message
news:30c7c456-a5f2-43ad-80fa-...
> During configuration of the Network Load Balancer on Win2003
> Server, when a rule is configured to have “Single” Affinity, on what
> basis does the load balancer decide which node is to be used? Is
> it the IP address from which the request is received?

It is based on the socket.

> If that is so, if multiple clients which are behind a public gateway
> try to access the server, the server will see the traffic coming from
> just one IP address. Will it serve the requests using the same host?

Yes. This is why it is often considered a best practice for Internet facing
NLB to use the Network (2008) or Class C (2003) Affinity options.

> From behind a gateway, is it possible to access the server in such
> a way that requests from one client are served by one host and
> requests from a second client are served by another? We need
> to do this for testing purpose.

Set affinity to none and after several connections, you should see a spread.
You can test it by making the pages on each NLB server just a bit different.
I usually put a 1 in the upper right hand corner for node one and a 2 in the
upper right hand corner of the second node. Then open multiple browsers and
you should see a mix between the two.


--
Russ Kaufmann,
MVP, MCSE: Messaging and Security, MCT, MCITP, MCTS and other stuff

ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp

"Yash" <> wrote in message
news:00f49e05-74d4-4cd0-8cf3-...

>
> > From behind a gateway, is it possible to access the server in such
> > a way that requests from one client are served by one host and
> > requests from a second client are served by another? We need
> > to do this for testing purpose.

> Our customer wants to configure the NLB for stickiness. So
> setting it to None is not an option.

I am sorry that None was confusing. I was responding to your need to test
the application as well as testing NLB distribution. Of course you don't
want to set it to None for production. That defeats the purpose of having
Affinity.

I recommended setting it to none so that you could verify distribution
between nodes was working, not as a permanent setting, and I apologize that
I was not clear about that step.


--
Russ Kaufmann,
MVP, MCSE: Messaging and Security, MCT, MCITP, MCTS and other stuff

ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp