Topic Last Modified: 2010-12-13

You can use the Registrar to configure proxy server authentication protocols. For information about the available protocols, see Create a New Registrar.

We recommend that you enable both Kerberos and NTLM when a server supports authentication for both remote and enterprise clients. The Edge Server and internal servers communicate to ensure that only NTLM authentication is offered to remote clients. If only Kerberos is enabled on these servers, they cannot authenticate remote users. If enterprise users also authenticate against the server, Kerberos is used.

Follow these steps to modify an existing Registrar.

To modify an existing Registrar

  1. From a user account that is a member of the RTCUniversalServerAdmins group (or has equivalent user rights), or assigned to the CsServerAdministrator or CsAdministrator role, log on to any computer that is in the network in which you deployed Lync Server 2010.

  2. Open a browser window, and then enter the Admin URL to open the Lync Server Control Panel. For details about the different methods you can use to start Lync Server Control Panel, see Open Lync Server Administrative Tools.

  3. In the left navigation bar, click Security and then click Registrar.

  4. On the Registrar page, click a service, click Edit, and then click Show details.

  5. In Edit Registrar Setting, select one or more of the following depending on the capabilities of the clients and support in your environment:

    • Enable Kerberos authentication to have the servers in the pool issue challenges using Kerberos authentication.

    • Enable NTLM authentication to have the servers in the pool issue challenges using NTLM.

    • Enable certificate authentication to have the servers in the pool issue certificates to clients.

  6. Click Commit.