Sure, on the ubee modem DHCP reservation is found as follows:
Login as admin:
Basic >> DHCP -> (bottom of the screen) DHCP Clients
The ubee modem has considerable trouble with the NEST thermostat. When the NEST is busy, it puts the network connection in standby. Apparently there an established protocol for this function. When the NEST sends the RESUME command the ubee modem ignores it and the connection is lost. I ended up plugging my power hungry LINKSYS router into the ubee modem to provide connectivity to the NEST. So far this problem had not affected the Arduino version of opensprinkler. I am mentioning it because it could conceivably affect the other hardware versions.