6.2.1 Communication settings when JP1/Base is used on multiple networks
This subsection describes communication settings required when a logical host is used on a physical host that is connected with multiple networks through multiple NICs, based on the system configuration example shown in the following figure.
- Organization of this subsection
(1) Conditions
The communication settings need to be changed if the following conditions are satisfied:
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hostA has 2 NICs and each of them is part of a separate subnet.
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The host name of hostA (physical host) resolves to the IP address 10.0.0.10 and the host name of logicalA (logical host) resolves to the IP address 20.0.0.10.
(2) Concept of communication
The physical host hostA is handled as a host within subnet1 and the logical host logicalA behaves as a host connected to subnet2 only. In this case, hostX in subnet1 can communicate with hostA, but not with logicalA. Similarly, hostY, which is in subnet2, can communicate with logicalA, but not with hostA. Therefore, you must change the communication settings to enable communications between hostX and logicalA and between hostY and hostA.
(3) Communication settings
To enable communication between all hosts, you need to configure the routing between subnets (there is no need to change the communication settings of JP1/Base). For information about the port numbers used in JP1/Base, see C.1 Port numbers for JP1/Base. By specifying routing settings, you can enable communications between hostX and logicalA, and between hostY and hostA.
You might not want to configure the routing settings for several reasons, such as your networks do not support routing, or you do not want to allow communications between subnets. If this is the case, you can change the communication settings to use JP1/Base in an environment of distinct networks. This functionality is called multi-LAN connectivity, and has been supported from JP1/Base 06-71. For details, see 6.5 Using JP1/Base in an environment of distinct networks (with jp1hosts information) and 6.6 Using JP1/Base in an environment of distinct networks (with jp1hosts2 information).