Advanced Operations › Network Configuration Details › Network Addresses › Private Network

Private Network

The private network is used by CA 3Tera AppLogic for the following key purposes:

• Control communication between the servers and the grid controller
• Storage access for appliances (similar to a storage network)
• Private inter-appliance communications

CA 3Tera AppLogic uses the following IP subnets on the private network:

• 192.168.0.s/24, where s is the server number in the backbone (1..254). Network addresses are assigned by the Backbone Fabric Controller during the discovery process and are no longer manually assigned.
• 192.168.N.i/24, where N is the grid number of the grid in the backbone and i is the server number within the grid. The range of N is 1..31; the range of i is 1..254 (currently, 1..32, as the max. number of servers in a grid is 32 in the 1.2.x releases). Addresses in this subnet are automatically assigned by CA 3Tera AppLogic to a server when a server boots up as part of a grid. These addresses should not be manually assigned or changed by the grid administrator.
• 192.168.255.0/24. This subnet is used by the grid installer to perform various tests when creating new grids and adding servers to the grid. No servers or appliances should use addresses from this subnet in order not to interfere with the installer (15 Mar 2007 -- holds true for all CA 3Tera AppLogic 1.2.x releases)
• 10.A.B.C/13, where A is calculated as N*8 and N is the grid number within the backbone (as above). The remainder of A, B, C is freely assigned by CA 3Tera AppLogic to appliances running on the grid, with the last valid address being reserved for the grid controller appliance (10.(N*8+7).255.254). Optionally, this address can be changed to 1.A.B.C/13 on a per-grid basis in CA 3Tera AppLogic.
• CA 3Tera AppLogic versions

The routes on servers and appliances are properly configured with the subnet masks and NIC devices, so that these addresses will always be routed to the private network (unless otherwise reconfigured explicitly by the grid administrator or CA 3Tera AppLogic user with root access -- the same way as if they were configured on physical servers).

Each grid uses only the private addresses belonging to it; this helps ensure that multiple grids (with different grid numbers N) can coexist on the same backbone.