Omron CJ1W-EIP21 - 10-2010 Operation Manual page 136

Private and Global Addresses
108
• With FINS/UDP, when the IP address (private address) of a computer
serving as a DHCP client is changed, the IP address conversion method
of the EtherNet/IP Unit or built-in EtherNet/IP port will be the automatic
generation method (dynamic), the combined method, or the IP address
table method. When FINS/TCP is used, IP addresses can be changed
automatically.
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Explicit Message Communications Service
• The explicit message communications service can be executed on the
intranet between EtherNet/IP Units and built-in EtherNet/IP ports with pri-
vate addresses only.
• A device such as a personal computer (CIP applications including the
Network Configurator) cannot connect online and communicate over the
Internet with an EtherNet/IP Unit or built-in EtherNet/IP port that has a pri-
vate address. Explicit message communications are also not possible
over the Internet between EtherNet/IP Units and built-in EtherNet/IP ports
with private addresses.
Note Network Security and Firewalls
Setting up an intranet through a global address involves network security con-
siderations. Before doing so, be sure to consult with a network specialist and
consider installing a firewall.
Once a firewall has been set up by a communications technician, on the other
hand, there may be some applications that cannot be used. Be sure to check
first with the communications technician.
Section 5-3