Example 3 — Multiple Application Servers on Different Subnets
It is common in larger iControl configurations to have multiple Application Servers on different subnets. Lookup services allow Application Servers from one subnet to share information with Application Servers on another subnet.
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1. For the purpose of this example, Alpha is the only Application Server running the Lookup Service on Subnet A. Under actual conditions, you should have two Application Servers (per subnet) running the lookup service in order to provide redundancy.
2. A GSM is active on Alpha.
3. The discovery process will result in all devices and services on Subnet A automatically registering with Alpha’s Lookup Service. If a client PC opens iC Navigator from Alpha, all Subnet A devices and services will be visible in iC Navigator.
4. As mentioned above, as a result of the discovery process, all devices and services on Subnet A will automatically register with Alpha’s Lookup Service. So it would not ordinarily be necessary to type anything in Bravo’s Service and alarm discovery area. However, if a client PC opens iC Navigator (or any client application) from Bravo, it will not see anything unless there is an IP address (either Alpha’s or Charlie’s) entered in Bravo’s Service and alarm discovery area.
IMPORTANT: System behavior |
If the Service and alarm discovery table of Application Servers is empty, client applications on the local Application Server can see services and alarms coming from the local GSM and all active GSMs on Application Servers within the subnet. |
5. The discovery process will result in all devices and services on Subnet B automatically registering with Charlie’s Lookup Service. If a client PC opens iC Navigator from Charlie, all Subnet B devices and services will be visible.
6. If this client PC has access to Subnet A (e.g. via VPN), it can access Alpha’s iControl—Startup page from a Web browser, and download iC Navigator (or any client application). The application knows about the Lookup Service on Alpha, and so the client PC will be able to see all devices and services registered on both Alpha and Bravo. Similarly, downloading an application from Charlie would make all of the devices and services on Subnet B visible.
However, in order for that same client PC to be able to see services and devices from both Subnet A and Subnet B, the IP addresses of both Alpha and Charlie, must be typed in each other’s Service and alarm discovery areas.
NOTE: The order in which the IP addresses are typed is not important. |
