I have followed all the steps mentioned at http://help.salesforce.com/HTViewSolution?id=000205653
Domain configured: abc-def.ghi.jk.lm ("abc-def" is a sub domain to "ghi.jk.lm domain")
CName in my DNS Management: abc-def.ghi.jk.lm.00d..........live.siteforce.com
When I am pointing a domain to my hosting IP, then the domain is working fine, but when I point it to Salesforce through a CNAME it is going to server not found.
I have contacted hosting provider and they said all is working fine at their end, which seems to be a fair statement as it is not working only when I am having a CNAME.