If you plan to host and publish websites to separate servers, make sure that these servers are properly resolved from the core server and are accessible over HTTP and FTP. You might need to manually configure DNS zones to ensure resolving of the publishing servers.
According to Requirements for Publishing Servers :
Regardless of whether you plan to host customers' sites on the same core server or separate servers, ensure that the following additional requirements are met:
The servers are resolvable on the Internet: DNS settings are properly configured.
PHP version 5.2 or later is installed.
PHP supports multibyte string functions (mbstring extension).
In php.ini, the following directive is set: default_charset = "UTF-8"