When I tried to run clients on different hosts (for my Virgina and NYC JUG) I ran into lots of frustration getting the client L1 to connect across a network to the L2. After lots of frustration, I uncovered that the following won't work (in the case of no DNS):
<server name="www.xxx.yyy.zzz" />
Where www.xxx.yyy.zzz is a real IP address such as 192.168.1.102
The problem? Simple. name only applies to a DNS-mappable name and IP addresses must be set in the host="" block of the same server config setting. This is not very normal behavior. Most software detects that a hostname is actually an IP address and has no issues being used in that manner.