How to keep user requests on the same server when using IIS NLB?

iis session nlb
Sergejus picture Sergejus · May 15, 2009 · Viewed 21k times · Source

I have two IIS servers running using NLB. Unfortunatelly I cannot use shared session server, so every server is using its own session. How can I ensure, that all requests from the same user are forwarded to the same IIS server?

Answer

Sergejus picture Sergejus · May 15, 2009

Found this and decided to share with others:

Use the client affinity feature. When client affinity is enabled, Network Load Balancing directs all TCP connections to the same cluster host. This allows session state to be maintained in host memory. You can enable client affinity in the Add/Edit Port Rules dialog box in Network Load Balancing Manager. Choose either Single or Class C affinity to ensure that only one cluster host will handle all connections that are part of the same client session. This is important if the server application running on the cluster host maintains session state (such as server cookies) between connections. For more information about Network Load Balancing affinity, see Help in the Network Load Balancing snap-in.

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