Thank you for your response, much appreciated! Yes, I've done a ping (resolves fine), nslookups on all DNS servers defined (2x prod and 2xDR) all resolve the A record, and a reverse lookup that works as well. I had thought DNS as well however, it works almost all the time. It simply stops working every 12-14 days. The Vserver configuration does appear to be similar if not exact to other vservers on this ONTAP cluster.
Another thing that caught my attention was SID compression since this is a Windows 2012 R2 server, however we're running a vesrion of CDOT where this particular issue has been patched (8.2.3 P3, and yes I know this is an older version. I'm working on it...)
If I do figure this out I'll be sure to post the resolution as I'm sure others out there have experienced similar issues.
THank you,
Brent