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CHAPTER2 Ethernet Unit
■ Example 5
In this example, a controller in a remote location is centrally managed over the Internet.
Use of a firewall (defense mechanism to keep out intruders) is recommended to maintain
security.
Factory 2
Controller
Controller
Internet
Factory 2
Factory 1
Router
Router
Head office
Router
Router
HUB
HUB
PC
PC
HUB
HUB
Internet
Internet
Internet
Head office router
PC
Factory 1 router
Controller 1
Factory 2 router
Controller 1
IP address
133.215.0.1
133.215.0.2
133.215.1.1
133.215.1.2
133.215.2.1
133.215.2.2
Subnet mask
255.255.255.0
255.255.255.0
255.255.255.0
255.255.255.0
255.255.255.0
255.255.255.0
Gateway
133.215.0.1
133.215.1.1
133.215.2.1
System setup example
* Routers must be set to match system conditions.
* To make a connection over the Internet, a global address must be set in the IP address.
* Use of identical addresses is not allowed so customers must not use the addresses set in the
above example.
Always use the customer’s own unique address. NIC (in Japan, JPNIC) handles the
assigning and management of addresses.