This topic describes how to configure the Domain Name System (DNS) records that you are required to create in all Office Communications Server deployments and those required for automatic client sign-in. When you create an Enterprise pool or deploy a Standard Edition server, Setup creates Active Directory objects and settings for the pool or server, including the pool or server fully qualified domain name (FQDN). For clients to be able to connect to the pool or server, the FQDN of the pool or server must be registered in DNS.

Important:
This topic assumes that you already know what DNS records you must configure for Office Communications Server and those required for automatic client sign-in. For details about the DNS records required to deploy your Enterprise pool or Standard Edition server, see the DNS Requirements for Serverstopic in the Office Communications Server 2007 R2 Planning and Architecture documentation.

Create and Verify DNS SRV and A Records for Client Automatic Client Sign-in

You must create DNS SRV records in your internal DNS for every Session Initiation Protocol (SIP) domain. The procedure assumes that your internal DNS has zones for your SIP user domains.

To create a DNS SRV 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 SIP domain in which your Office Communications Server will be installed.

  3. Click Other New Records.

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

  5. Click Service, and then type _sipinternaltls.

  6. Click Protocol, and then type _tcp.

  7. Click Port Number, and then type 5061.

  8. Click Host offering this service, and then type the FQDN of the pool.

  9. Click OK.

  10. Click Done.

After you have created the DNS SRV record, create a DNS A record. For Enterprise Edition, create a DNS A record for each pool FQDN and URL FQDN that is not the same as the server FQDN. For Standard Edition, create a DNS A record for the Standard Edition server.

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 domain, expand Forward Lookup Zones, and then right-click the domain in which your Office Communications Server will be installed.

  3. Click New Host (A).

  4. Click Name (uses parent domain name if blank), and then type the name of the server or pool.

  5. Click IP Address, and then do one of the following:

    • For Enterprise Edition, type the VIP of the load balancer.

    • For Standard Edition, type the IP address of the Standard Edition server.

    Note:
    If you deploy only one Enterprise Edition server that is connected to the back end without a load balancer, type the IP address of the Enterprise Edition server. A load balancer is required if you deploy more than one Enterprise Edition server in a pool.

  6. Click Add Host, and then click OK.

  7. To create an additional A record, repeat steps 4 and 5.

  8. When you are finished creating all the A records that you need, click Done.

To verify that the required records have been created successfully, wait for DNS replication (if you have just added the records), and then verify that the records were created as described in the next procedure.

Note:
For illustrative purposes, the following steps use example.com as the domain portion of the SIP URI namespace. When performing these steps, use your actual SIP domain name instead.
To verify the creation of a DNS SRV record

  1. Log on to a client computer in the domain with an account that is a member of the Administratorsgroup or has equivalent permissions.

  2. Click Start, and then click Run.

  3. In the Openbox, type cmd, and then click OK.

  4. At the command prompt, type nslookup, and then press ENTER.

  5. Type set type=srv, and then press ENTER.

  6. Type _sipinternaltls._tcp.example.com, and then press ENTER. The output displayed for the TLS record is as follows:

    Copy Code 
    Server:  <dns server>.example.com
Address:  <IP address of DNS server>
Non-authoritative answer:
_sipinternaltls._tcp.example.com SRV service location:
		priority	 = 0
		weight		 = 0
		port		 = 5061
		svr hostname   = poolname.example.com
poolname.example.com	 internet address = <virtual IP
Address of the load balancer> or <IP address of a single
Enterprise Edition server for pools with only one Enterprise
Edition server>

  7. When you are finished, at the command prompt, type exit, and then press ENTER.

After you configure the DNS records, verify that the FQDN of the Standard Edition server or Enterprise pool can be resolved by DNS.

To verify that the FQDN of the Enterprise pool or Standard Edition server can be resolved

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

  2. Click Start, and then click Run.

  3. In the Openbox, type cmd, and then click OK.

  4. At the command prompt, type ping <FQDN of the Enterprise pool or Standard Edition server>, and then press ENTER.

  5. Verify that you receive a response similar to the following, where the IP address returned is one of the following:

    • For Enterprise Edition, the IP address of the load balancer for your Enterprise pool or, in the case of an Enterprise pool with a single Enterprise Edition server, the IP address of the Enterprise Edition server.

    • For Standard Edition, the IP address of the Standard Edition server.

    Copy Code 
    Reply from 172.27.176.117: bytes=32 time<1ms TTL=127
Reply from 172.27.176.117: bytes=32 time<1ms TTL=127
Reply from 172.27.176.117: bytes=32 time<1ms TTL=127
Reply from 172.27.176.117: bytes=32 time<1ms TTL=127

See Also

Other Resources

Client DNS Queries Drilldown