Addtron Technology TW-640 - Manual (Page 12)

Quick Start Guide
11
Ⅱ . Cable users (Dynamic):
Users who do not have static
IP addresses from their ISPs.
Ⅲ . xDSL/Cable users (Static):
Users who have obtained at least
one dedicated IP address from an
ISP.
Please also check that DNS setting is
ccorrect (Automatic is the best setting).