DNS A record for sub-subdomain when subdomain is a CNAME

cname-recorddomain-name-system

Is it possible to create an A record for a sub-subdomain when the subdomain has been CNAMEd? Something like this:

domain.com           A       198.51.100.1
my.domain.com        CNAME   othersite.com
www.my.domain.com    A       198.51.100.1

Will the CNAME on my.domain.com cause the lookup for www.my.domain.com to fail, or cause any other ill effects?

Best Answer

That wouldn't have any impact whatsoever.

The DNS query will start by looking up the sub-domain in its cache and if it's not found, it will look up the NS record for the zone and query it (your DNS server) for the subdomain. It won't even notice the CNAME that worries you.

Related Topic