two primary's

[Robert Spangler]

On Wednesday 05 March 2008 22:34, Kevin Darcy wrote:

>  > While everyone has his/her opinion on this, I believe you can run 2
>  > master servers together on the same network.  One just needs to be a
>  > little clever in doing it.  I have a test lab setup (2 Masters, 4
>  > Slaves) where I have played with this idea and it functions.  The idea
>  > is to be able to switch to the second master and make updates without
>  > having to make a bunch of configuration changes.
>  >
>  > The setup is simple enough, you just have to tell each master that the
>  > other is the master of the zone and to notify the other when it is
>  > updated.

[config removed]

>  > Now when ever A is updated it will notify all the other DNS servers
>  > including B.  Should A go off line then you can still update B and it
>  > will continue to update the slaves.  When A comes back on-line again it
>  > will poll B for the latest and it too will be updated with the latest
>  > information.  You then can decide to continue updating B or switch back
>  > to A and have nothing missing or take the change that you fat fingered
>  > something in the config files while switching masters.
>
>  Important caveat: every time you want to make a change to A, you need to
>  ensure that either i) A's copy of the zone is fully sync'ed with B, or
>  ii) the changes made to A's zone are a *superset* of the changes which
>  were made to B's zone since the last refresh, and the serial  number is
>  set sufficiently high to prevent the refresh from happening. And
>  _vice_versa_ when making changes to B. Failure to heed these precautions
>  may result in your changes being wiped out by the next zone refresh from
>  the other "master".

If everything is setup correctly then this should not be an issue as when 
either server is updated they will update the other.  The "Important caveat" 
here is to ensure you are only updating one master server.  This design is 
for fail over only.  It is not intended that one person update A while 
another update B.  That would only lead to problems down the road.


-- 

Regards
Robert

Smile... it increases your face value!
Linux User #296285
http://counter.li.org