Facility wide DR/Continuity
brandon.galbraith at gmail.com
Wed Jun 3 09:53:12 CDT 2009
On Wed, Jun 3, 2009 at 9:37 AM, William Herrin <herrin-nanog at dirtside.com>wrote:
> On Wed, Jun 3, 2009 at 8:09 AM, Drew Weaver<drew.weaver at thenap.com> wrote:
> If you can't afford the fiber or need to put the DR site too far away
> for fiber to be practical, you can still build a network which
> virtualizes your LAN. However, you then have to worry about issues
> with the broadcast domain and traffic demand between the clustered
> servers over the slower WAN.
> It's doable. I've done it with VPNs over Internet T1's. But you better
> have your developers on board early and and provide them with a
> simulated environment so that they can get used to the idea of having
> little bandwidth between the clustered servers.
In most cases, the fiber is affordable (a certain bandwidth provider out
there offers Layer 2 point to point anywhere on their network for very low
four digit prices). We recently put into place an active/active environment
with one end point in the US and the other end point in Amsterdam, and both
sides see the other as if they were on the same physical lan segment. I've
found that, like you said, you *must* have the application developers
onboard early, as you can only do so much at the network level without the
app being aware.
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