OK guys, I really looked all over for an answer, but couldn't find the right one.
Background: Windows 2008R2 AD integrated DNS in abc.com (let's say). We are preparing to migrate to Office 365, and are currently using Lync. I have created the CName records for Lync as follows: sip.abc.com = sipdir.online.lync.com and lyncdiscover.abc.com = webdir.online.lync.com.
Here is the output of my nslookups:
nslookup lyncdiscover.abc.com
Server: UnKnown
Address: ::1
Name: webdir.online.lync.com
Addresses: 2a01:111:f404:c07::38
132.245.1.28
Aliases: lyncdiscover.abc.com
**************************************
nslookup sip.abc.com
Server: UnKnown
Address: ::1
Name: sip.abc.com
*****************************************
So, I checked DNS settings and found a couple of minor issues, which I quickly fixed. And yes, the servers can resolve webdir.online.lync.com just fine. Nevertheless, I can't figure out why the servers would resolve one CName, but not the other?
The "server:unknown" is no big deal as it will resolve to localhost.
But, if the servers can resolve both alias', why would DNS resolve the one CNAME record, yet not the other?