Are you connecting to each robot wirelessly from the laptop driver stations?
If so then the simplest way to connect to multiple robots is to browse to the DLink on one of the robots and change it's SSID (under Wireless). Then tell each laptop to connect to different DLinks identified by their unique SSID.
That keeps the two (or more) robot networks completely separate and having common IPs won't matter.
Step-by-step directions at:
http://www.chiefdelphi.com/forums/sh...50#post1486250
The 172. IP address is only for connecting via USB and would only be a problem if you tried to connect a single laptop to both robots via two USB cables.