PTP 450 Configuration and User Guide
Data network planning
4-32
pmp-0815 (August 2015)
Data network planning
This section describes factors to be considered when planning PTP 450 data networks.
Understanding addresses
A basic understanding of Internet Protocol (IP) address and subnet mask concepts is
required for engineering your IP network.
IP address
The IP address is a 32-bit binary number that has four parts (octets). This set of four octets
has two segments, depending on the class of IP address. The first segment identifies the
network. The second identifies the hosts or devices on the network. The subnet mask
marks a boundary between these two sub-addresses.
Dynamic or static addressing
For any computer to communicate with a module, the computer must be configured to
either:
Use DHCP (Dynamic Host Configuration Protocol). In this case, when not connected to
the network, the computer derives an IP address on the 169.254 network within two
minutes.
Have an assigned static IP address (for example, 169.254.1.5) on the 169.254 network.
If an IP address that is set in the module is not the 169.254.x.x network address, then the
network operator must assign the computer a static IP address in the same subnet.
When a DHCP server is not found
To operate on a network, a computer requires an IP address, a subnet mask, and possibly a
gateway address. Either a DHCP server automatically assigns this configuration
information to a computer on a network or an operator must input these items.
When a computer is brought on line and a DHCP server is not accessible (such as when the
server is down or the computer is not plugged into the network), Microsoft and Apple
operating systems default to an IP address of 169.254.x.x and a subnet mask of
255.255.0.0 (169.254/16, where /16 indicates that the first 16 bits of the address range are
identical among all members of the subnet).
DNS Client
The DNS Client is used to resolve names of management servers within the operator’s
management domain (see
). This feature allows hostname configuration for NTP
servers, Authorization Servers, DHCP relay servers, and SNMP trap servers. Operators
may choose to either enter in the FQDN (Fully Qualified Domain Name) for the host name
or to manually enter the IP addresses of the servers
.
