[lug] Virtual Hosting and DNS

[Michael Shuler]

jdavis wrote:
>  it appears to be ok to have multiple  
>  A records for a IP addy ,But it looks like the common method

Multiple A records are fine - I do not believe this really matters, 
other than 'standard practice' for a DNS admin.

>  of DNS setup for name-based virt web hosts is to use CNAME.
> 
> #############################################################
>   i.e.
>   second_domain.com CNAME first_domain.bz
> 

Hmm - now in the small amount of DNS I have done, your example would 
seem to translate to:

second_domain.com.first_domain.bz -> is an alias for first_domain.bz

...if this is contained in the zonefile for first_domain.bz. I see what 
you are going for, but this does not work in the zone file for 
first_domain.bz, since second_domain.com is still not a resolvable FQDN.

>   or
>   
>   second_domain.com  A   1.2.3.4
> 
>  where 1.2.3.4 is also the IP of first_domain.bz and
>  first_domain.bz is the primary domain hosting all others.
> 
> #############################################################
> 
> Are there pros or cons to either way as far as HTTP and SMTP
> are concerned.

DNS is merely translating a name to a number.  If you get to the number 
one way or another, I do not believe it makes much of a difference on 
the small scale.  If an IP/DNS admin would like to chime in, please, 
extoll the virtues of proper zone juju on the large scale.  :)

Michael