[CentOS] DNS wizard
Maciej Żenczykowski
maze at cela.pl
Tue Jan 3 20:03:50 UTC 2006
> But there is no down side to a CNAME as long as you remember
> that it really is an alias for the target name and thus inherits
> any other data (like MX records) associated with it.
The downsides to CNAMEs is that they increase look-up times - instead of
getting an IP, you get a hostname which you have to look-up - again (ie.
basically if your unlucky it's double the hostname -> IP/MX/whatever
lookup time). ie. back to square one. Furthermore anything which is a
CNAME point to a CNAME is dangerous - and those have a tendency to
automagically crop up. Depending on the DNS library/cache etc you are
using already 3 CNAME's in a row may result in failed lookups (others have
higher limits - sometimes 4 sometimes as high as 10, sometimes none...)
Cheers,
MaZe.
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