there is no native support for this.
There is a solution http://www.syncdek.com/syncdek/ tht should cover this, I myself have never tried it.
I use the XML webpublishing to sync data between servers over the internet, works pretty well. I only sync once a day to get the data I need from one server to the other.
If you want to mirror a solution it's pretty simple: you can directly call FileMaker XML and import the data into your secondary server.
Snycing both ways is another, much more complicated issue.
You can call FileMaker XML via url and directly import it, but the errorhandling is not perfect, I had timeouts that took forever. I use
360Works Web Assiant http://360works.com/url-plugin/ to get the urls, the error handling is much better and reliable. (As free alternative you could also use 360Works ScriptMaster GetUrl() ).
You could also consider having your solution hosted, there a few companies around offering FM hosting via the web.