Re: Mirroring Systems

["Lukas Beeler" <lukas.beeler@xxxxxxxxxxxxxxxx>]

On Feb 10, 2008 8:17 PM, Ken Sims <mdrg7319@xxxxxxxxxxx> wrote:
> One issue, our disaster recovery system is in a completely different
> location from our main system (as it should be), several hundred miles
> away, and so it's on a different subnet (192.168.251.0/24 versus
> 192.168.10.0/24).  So it would involve more than just having the
> disaster recovery system use the main system's IP address.  The
> packets would never get routed to that subnet.

There are many ways to do this. The simplest solution is to use DNS
with a low TTL, but of course that has several drawbacks.

Using a seperate subnet for the cluster is the solution usually
implemented, and routing changed dynamically. If that is not possible,
policy routing, NAT are other ways to achieve the same result.

> It would be possible to have the disaster recovery center be on the
> same subnet as the main data center, but it wouldn't be easy.

I wouldn't use that approach either.