DNS SRV record Lync 2010

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 Standard Edition Server.
9. Click OK.
10. Click Done.

Or you can create this by using Powershell

New-DnsRecord -RecordType SRV -Server yourdnsserver.yourdomain.com -ZoneName yourdnszone.com -TTL 3600 -Priority 0 -Weight 0 -Port 5061 -TargetName lyncpool.yourdomain.com -Name "_sipfederationtls._tcp"

If you do not have the DNSShell you can download it here: http://dnsshell.codeplex.com/

Installation

1. Extract DnsShell.zip to C:\Windows\System32\WindowsPowerShell\v1.0\Modules\DnsShell
2. Run: Import-Module DnsShell