Building Automation Knowledge Base

Issue How is a subnet defined? Environment Refer to "TCP/IP Network Administration" by Craig Hunt, O’Reilly & Associates, Inc. Cause Sectioning network communication by subnets. Resolution A subnet is defined by applying a bit mask (subnet mask) to the IP address. If a bit is on in the mask, that equivalent bit in the address is interpreted as a network bit. If a bit in the mask is off, the bit belongs to the host part of the address. The subnet is only known locally.