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domain name system - Dns - wildcard vs. cname subdomains

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Alright I have to admit I'm confused
with how DNS works. I've always just added things until they worked, and now it's time
to learn how they work.



So one confusing thing
to me is that there's sort of two places I can have records. I have an account with
rackspace cloud servers. And then there's the place I registered the domain. But both
allow me to edit DNS records.




Should
I do everything at both places or is one better than the other or am I missing the
point?



Subdomains confuse me too. I'd like to be
able to just have a wildcard subdomain (I've done this in the past.) I just don't like
the idea of adding a cname record or A record every time I need a new
subdomain.



Then I read href="http://en.wikipedia.org/wiki/Wildcard_DNS_record" rel="nofollow
noreferrer">this and it
says:




The exact
rules for when a wild card will match are specified in RFC 1034, but the rules are
neither intuitive nor clearly specified. This has resulted in incompatible
implementations and unexpected results when they are
used.



class="post-text" itemprop="text">
class="normal">Answer





The first thing you need to do is determine who actually serves authoritative
answers for your domain name. A WHOIS lookup will tell you which DNS servers are the
ones where you should be making changes.



Once
that is determined, make the changes with the provider listed and get rid of everything
else to avoid any future confusion.



Regarding
wildcards vs. hostnames, do whatever you're comfortable with. In general, most DNS
implementations will look for a hostname that's been specifically defined (i.e. an
A record that directs to a specific IP address) and will fall
back to a wildcard if none is found. Personally, I prefer to define each of my records
individually. This way I know what I have and where it goes without any questions.
Wildcards can be great if you have 300 hostnames that all need to go to the same place
and they change all the time. If you only have a handful of hostnames and they don't
change often, I'd opt for setting them up
individually.



If you have a dozen hostnames that
all need to go to the same IP, you can define one of them as an
A record, and make the rest CNAME
aliases of the first one. This way, you only need to update that IP address
once.


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