2.3.3 Connecting multiple LANs
JP1/AJS3 supports system configurations where JP1/AJS3 - Manager, JP1/AJS3 - Agent, or JP1/AJS3 - View is installed in a server (host) and multiple LANs are connected to this server (host).
To be able to use JP1/AJS3, you need to define one of the following in order to obtain IP addresses from the host names of the connection target hosts:
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DNS server
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hosts file
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jp1hosts file or jp1hosts2 file
The following figure shows an example of a system configuration for communicating with a host connected to multiple LANs.
In this configuration, you need to specify settings so that when HostA attempts to acquire the IP address of HostB, it acquires the LANA_B IP address. Similarly, specify settings so that when HostC attempts to acquire the IP address of HostB, it acquires the LANB_B IP address.
Assuming that the above prerequisites are met, the following are tips for using JP1/AJS3 on a host connected to multiple LANs.
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Whether the communication protocol for multiple LAN connections has been set for JP1/Base
If the communication protocol for multiple LAN connections has been set for the JP1/Base communication setting, the JP1/AJS3 communication protocol is determined by this setting. See (1) Communication protocols for sending or receiving data and (2) Methods for resolving host names to make sure you can use JP1/AJS3 with the current settings.
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Whether to set multiple LAN connections if the communication protocol for multiple LAN connections for JP1/Base has not been set
The following are important considerations regarding the JP1/Base communication settings:
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Selection of the communication protocol for sending or receiving data
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Host name resolution methods (defining jp1hosts information or jp1hosts2 information)
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For details about JP1/Base multiple LAN connections, see the description about using JP1/Base in a dissociated network environment in the JP1/Base User's Guide.
- Organization of this subsection
(1) Communication protocols for sending or receiving data
The table below shows the communication protocols that are available after JP1/AJS3 has been set up. The communication protocol varies according to whether multiple LAN connections provided by JP1/Base have been set in advance. For details about how to check the current settings, see the description of the JP1/Base communication protocols in the JP1/Base User's Guide.
The following table explains communication protocols available after JP1/AJS3 has been set up.
Communication protocol for physical hosts |
Communication protocol for logical hosts |
||||
---|---|---|---|---|---|
Send |
Receive |
Send |
Receive |
||
Multiple LAN connections have not been set#1 |
Immediately after installation |
ANY binding |
ANY binding |
-- |
-- |
Immediately after cluster setup |
IP binding |
IP binding#2 |
IP binding |
IP binding#2 |
|
Multiple LAN connections have been set#1 |
Immediately after installation |
Same as JP1/Base |
Same as JP1/Base#2 |
-- |
-- |
Immediately after cluster setup |
Same as JP1/Base |
Same as JP1/Base#2 |
Same as JP1/Base |
Same as JP1/Base#2 |
- Legend:
-
--: Not applicable
- #1
-
Note that when an OS that allows the user to acquire multiple IP addresses from a single host name is used, the event/action control function and the job execution control function operate differently as follows.
- When the communication protocol for multiple LAN connections has not been set for JP1/Base
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Acquired IP addresses are used one after another until a connection is successfully established.
- When the communication protocol for multiple LAN connections has been set for JP1/Base
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Of the obtained IP addresses, a connection is attempted only to the IP address at the beginning in the jp1hosts file or jp1hosts2 file.
- #2
-
ANY binding is used for the JP1/AJS3 Queueless Agent and JP1/AJS3 Check Agent services.
If IP binding is set for the transmission setting, data can be sent to only one LAN. In the configuration example shown in Figure 2-17, if the HostB transmission setting is IP binding, HostB can communicate with either LANA or LANB. For this reason, use ANY binding for the transmission setting of a host connected to multiple LANs, irrespective of whether cluster operation is used. When only physical hosts are used, you do not need to specify the setting because ANY binding is set immediately after installation. In a cluster system, you must set the communication protocol for multiple LAN connections of JP1/Base because IP binding is set immediately after cluster setup.
When ANY binding is set for the receive setting in a cluster system, data sent to a physical host might be received by a logical host, or data sent to a logical host might be received by a physical host. As a result, jobs cannot be executed correctly. To avoid this problem, IP binding must be set for the receive setting, irrespective of whether the host is connected to multiple LANs. The setting cannot be changed to ANY binding.
When IP binding is set for the receive setting, only data from a single host can be received. In the configuration example shown in Figure 2-17, if the HostB receive setting is IP binding, HostB can receive data from either HostA or HostC. When the communication protocol for multiple LAN connections of JP1/Base is specified, data from both LANA and LANB can be received as long as the receive setting is IP binding. Accordingly, if you want to set IP binding for the HostB receive setting, the communication protocol for multiple LAN connections of JP1/Base must be set on HostB.
The following table summarizes the above discussion.
Connection to multiple LANs |
||
---|---|---|
No |
Yes |
|
Operation using physical hosts only |
No problem occurs if the setting specified immediately after installation is used. |
No problem occurs if the setting specified immediately after installation is used. |
Cluster operation |
No problem occurs if the setting specified immediately after cluster setup is used. |
The communication protocol for multiple LAN connections of JP1/Base must be considered. |
Even for the cases in the above table for which there is no problem, you can permanently assign the LAN to be used for JP1/AJS3 by setting the communication protocol for multiple LAN connections of JP1/Base as necessary.
When JP1/AJS3 - Manager, JP1/AJS3 - Agent, and JP1/AJS3 - View are used in an environment in which multiple LANs are connected, the necessary settings vary according to the host on the LAN where a product is used. For details about these settings, see D. Communication Settings in Multiple-LAN Environments.
(2) Methods for resolving host names
For a host connected to multiple LANs, multiple IP addresses must be obtained from a single host name. In the configuration example shown in Figure 2-17, the LANA_B and LANB_B IP addresses must be acquirable as the IP addresses of HostB. However, depending on the OS, it might not be possible to acquire multiple IP addresses from a single host name. In addition, if the hosts use the same hosts file or DNS, and HostC attempts to acquire the IP address of HostB, the LANA_B IP address might be acquired but the LANB_B IP address might not be.
Even in these cases, you can obtain multiple IP addresses from a single host name for JP1/AJS3 communications by defining the jp1hosts information or jp1hosts2 information provided by JP1/Base. As a result, when HostC obtains the IP address of HostB, HostC can also obtain the IP address of LANB_B.
For details about jp1hosts and jp1hosts2, see the JP1/Base User's Guide.