Originally Posted by onastvar
I have two physical servers at two different locations setup using this guide
Could you please explain how to switch the IP?
Also, how put a loadbalancer in front, is there a guide to follow to set this up?
This is totally dependend on where you have your servers. As an example if you are with ovh you have to either rend a cisco hardware load-balancer or switch your fail-over-IP via the API if one servers fails. You could also use a vRack for this.
With some providers (mostly when they provide a private network for your servers only) it's also possible to simply use a gratuitous arp to take over the IP address (and the traffic) from another machine.
With the most providers I know, it's only possible to use fail-over-IPs between machines in the same datecenter due to routing limitations.
Either way, you got to see what options are offered by your provider for this case.