TRENDnet TW-H6W1IR - Manual (Page 152)

TW-H6W1IR ISDN Remote Router
144 Appendix B - IP Concepts
IP Class Subnet Mask
Class A 255.0.0.0
Class B 255.255.0.0
Class C 255.255.255.0
Subnet mask settings other than those listed above add significance to the interpretation of
bits in the IP address. The bits of the subnet mask correspond directly to the bits of the IP
address. Any bit an a subnet mask that is to correspond to a net ID bit in the IP address must
be set to 1.