Dnat to Snat and Vica versa RRS feed

  • Question

  • Does anyone know how to change your pool configuration for loadbalancing after it has been setup? IE , I configured the pool for snat and now want to switch to dnat.

    On a side note, why is snat the preferred method? What technically breaks when using Dnat?

    Friday, August 17, 2007 10:27 PM

All replies

  • Yes, why does OCS care.  Why does it ask that question during installation?  What happens if I answer it wrong?  Also I would like to know how to change it?  Also can I first install one server to the pool without a load balancer configured and then when I add in the second EE Consolidated server can I configure the load balancer then. My load balancer personnel do not know the difference between the two so I can I tell on a Load Balancer.  I just wish there was more documentation about this topic.


    Monday, November 12, 2007 4:01 PM

    SNAT for Load Balancer


    Using a load balancer in SNAT mode is recommended for ease of deployment, however be aware each SNAT IP address on the load balancer limits the maximum number of simultaneous connections to 65,000. If you deploy load balancer in SNAT mode, ensure you configure a minimum of one SNAT IP address for each group of 65,000 users. (The open number of connections generally corresponds to the number of active users.) For example, in a deployment supporting 100,000 users, you would configure two SNAT IP addresses.


    DNAT For Load Balancer


    •If you use a DNAT (destination network address translation) load balancer for your Enterprise pools, the following is required:

    •Each pool must reside in a distinct IP subnet from other pools, because the Front End Servers in each pool must reside in this distinct IP subnet.

    •For a pool in the expanded configuration, only the Front End Servers must be placed in this distinct IP subnet. All other roles – the Web Conferencing, A/V Conferencing, and Web Components Servers – must reside outside the distinct IP subnet for the Front End Servers. There is no additional restriction on how these other roles can be placed on the network.

    •If you are planning to archive or if your organization has regulatory compliance requirements, determine if you want to deploy the Office Communications Server 2007 Archiving and CDR Server before you configure your Enterprise pool (You must create the pool before deployment). If you deploy the Archiving and CDR Server before you configure your Enterprise pool, you can configure archiving on your servers during the Enterprise Edition deployment process.


    To Select SNAT or DNAT in Load balancer we need to do the following:


     In the deployment tool, do one of the following:

    1.            Click Deploy Pools in a Consolidated Topology.

    2.            Click Deploy Pools in an Expanded Topology.

    3.                At Configure Pool, click Run.

    4.            On the Welcome to the Configure Pool/Server Wizard page, click Next.

    5.            Before you can continue, the Office Communications Server administration tools must be installed if they are not already on the computer. On the Administrative Tools required page, click Next to install the administrative tools.

    6.            On the Server or Pool to Configure page, select the pool from the list, and then click Next.

    7.On the Load Balancer Configuration Parameters page, do one of the following:

    8.If you are using a load balancer that is configured to perform DNAT (destination network address translation), click Load balancer is configured in DNAT (destination network address translation) mode.

    9.If you are using a load balancer that is configured to perform SNAT (source network address translation) or if you are not using a load balancer, click Load balancer is configured in SNAT (source network address translation) mode.

    Friday, November 16, 2007 12:53 AM