If you're creating an application where connecting on the "root domain" matters it can be problematic. For example, imagine you were creating some URL rewrites

If you're creating an application where connecting on the "root domain" matters it can be problematic. For example, imagine you were creating some URL rewrites using apache's mod_rewrite and they worked for http://some.domain.com/rewrite-goes-here/ http://some.domain.com/rewrite-goes-here/ you would have to do a bunch of extra work (or an extra set of rules even) to make that work also for 10.0.1.1/my_app_without_vhost/rewrite-goes-here/ When you're testing on your LAN using a PC/mac or whatever you can do a local DNS modification on the machine (eg. /etc/hosts) but when you're testing from an iPad or some other device this is either impossible or prohibitively difficult. The other option is to setup a DNS server on your LAN which is a headache all it's own - this is a very simple and elegant way of circumventing these issues. Awesome stuff.