Topic Last Modified: 2011-04-11

You must configure Domain Name System (DNS) records for internal and external edge interfaces, including both Edge Server and reverse proxy interfaces.

Note:
By default, DNS uses a round robin algorithm to rotate the order of resource record data returned in query answers where multiple resource records of the same type exist for a queried DNS domain name. Lync Server 2010 DNS load balancing depends on this mechanism. Verify that this setting has not been disabled. If you are using a DNS server that is not running a Windows operating system, verify that round-robin resource record ordering is enabled.

Use the following procedures to create and verify each DNS SRV record and DNS A record required for external user access. For details about each record required to support external user access, see Determining DNS Requirements.

To create a DNS SRV record

  1. On the appropriate DNS server, click Start, click Control Panel, click Administrative Tools, and then click DNS.

    Important:
    You need to configure DNS so that there are: 1) external DNS entries for external DNS lookups by remote users and federated partners; 2) entries for DNS lookups for use by the Edge Servers within the perimeter network (also known as DMZ, demilitarized zone, and screened subnet), including A records for the internal servers running Lync Server 2010; and 3) internal DNS entries for lookups by the internal clients and servers running Lync Server 2010.

  2. In the console tree for your SIP domain, expand Forward Lookup Zones, and then right-click the domain where Lync Server 2010 is installed.

  3. Click Other New Records.

  4. In Select a resource record type, type Service Location (SRV), and then click Create Record.

  5. Provide all required information for the DNS SRV record.

To create a DNS A record

  1. On the DNS server, click Start, click Control Panel, click Administrative Tools, and then click DNS.

  2. In the console tree for your SIP domain, expand Forward Lookup Zones, and then right-click the domain in which Lync Server 2010 is installed.

  3. Click New Host (A).

  4. Provide all required information for the DNS SRV record.

To verify a DNS record

  1. Log on to a client computer in the domain.

  2. Click Start, and then click Run.

  3. At the command prompt, run the following command:

    Copy Code 
    nslookup <FQDN edge interface>

  4. Verify that you receive a reply that resolves to the appropriate IP address for the FQDN.