Geographical Load Balancing

William Attwood wattwood at
Wed Nov 11 15:35:14 MST 2009

On Wed, Nov 11, 2009 at 3:27 PM, Steven Alligood <steve at> wrote:

> On 11/11/2009 03:19 PM, William Attwood wrote:
>> Hello--
>>    How does one accomplish geographical load balancing? With that in mind,
>> what about geographical failover?  Example, I have a data center (DC) in
>> Dallas, and another in Salt Lake.  How do I re-direct traffic if Dallas
>> goes
>> offline?
>>    Just a project I'm diving into.  colo-specific load balancing and
>> failover is accomplished, now we need to protect against the data center
>> going offline, and speed of access to machines.  I see how I can do
>> geographical failover with a geographical load balancer, however, do I
>> need
>> 2 geographical load balancers if one of them goes offline?
>>    Has someone here worked on a project of this magnitude?
> It';s been several years since I have set that up, but the old alteons (now
> owned by nortel) would do geographical load balancing with one in each
> location.
> Basically, you setup your auth dns to point to each location, with any
> subdomain in DNS delegated to the load balancer.  It would then give out dns
> based on which one it found to be quicker, etc, and in an outage would give
> just itself out for it's local farm.
> Of course, if you are doing IPv6, check out the anycast stuff.  Quite
> amazing.
> -Steve
> /*
> PLUG:, #utah on
> Unsubscribe:
> Don't fear the penguin.
> */

If one site goes offline, won't that mean 50% of my traffic also goes
offline, depending on which IP DNS feeds back?  I may have misunderstood

Take care,
William Attwood
Idea Extraordinaire
wattwood at

Stephen Leacock<>
- "I detest life-insurance agents: they always argue that I shall some
die, which is not so."

More information about the PLUG mailing list