I have 2 web servers running apache hosted at 2 data centres on 2 different IP ranges.

The 2 servers are an exact clone of each other hosting www.example.com.

What I am trying to achieve automatic failover. Say my first data centre gets wiped out, how would customers reach my website on my second server in the second data centre by still typing www.example.com?

The aim is for the customer not to notice any difference.

Hi -

Sounds like a fairly pricey service - and it sounds like you're either already paying for it, or you're a very likely potential customer - so the BEST thing you can do is to ASK your vendor(s).

If you want to Google for background information, the best "buzzwords" are:

* colocation (your "two centers" are also "colo facilities", aka "remote data center")

* IP failover (this is how you'd achieve failover between two distributed facilities)

We are LIR, so have a /20 ip address range associated with us.

In One site we are advertising a /23 from our /20 block, and in the other we are advertising different /23 from our /20 block.

We have BGP peering on each site. I am guessing we have the means to accomplish the high availability that I am aiming for without going through a third party??

Take a look this site: http://www.howtoforge.com/efficient-...routing-method it's about load-ballancing and high-available server setup.

You can find on "howtoforge" automatic file replication server setup as well. (but rsync can do file replication trick in many cases)
Anyway this service came from RedHat meaning 100% reliable.

But if you have your own BGP peering I guess you can do the same thing with Cisco load ballancing.
And the apache servers in the background can be rsynced to serve the same websites.
The hard part is not the apache rather than the database server.

To sync Mysql or any live database on a website, that has to be planned at the first place otherwise it won't work properly.
There is a mysql cluster install on debian: http://www.howtoforge.com/loadbalanc...cluster_debian just for a hints.

I hope it helped somehow.

Laz