Using Dynamic DNS for a Co-Location

[Ralf Durkee]

connah at gmail.com wrote:
> Hi all!
>
> My organization needs to establish a co-location in the event that our
> primary office loses power. The "co-location" will consist only of a
> computer running vital websites. I would like to understand how we can
> use DNS to accomplish this. The goal is that if website ABC.COM
> (1.1.1.1) goes down, we want some process in the co-location monitoring
> that. When it detects an outage, our DNS records need to be modified to
> point ABC.COM to 2.2.2.2 with as short of propagation time as possible
> (hopefully minutes, if not seconds).
>
> Can this be done? If so, how? Also, if you see that this is a
> ridiculous idea and have a better one, please suggest it! I don't much
> care HOW it gets accomplished. I just want the ultimate functionality
> of another box picking up for us.
>
> Thank you!
>
> Matthew
>
>
>   
Although some might consider it a mis-use of DNS, it can be and commonly 
is used for fail-over,  You might also consider  a round-robin 
configuration that sends traffic to both servers, and  then removes one 
address when one fails.  I've seen an example of a caching name servers 
ignored time-to-live times that we were very short, so you're a bit at 
the mercy of caching name server across the internet, not keeping the 
information longer than expected / desired.  If you don't have a strong 
technical staff. There are service providers specializing in DNS that 
will provide a failover service, that may be more cost effective than 
implementing your own.

-- Ralf Durkee, CISSP, GSEC, GCIH
Principal Security Consultant
http://rd1.net