Installation guide

Installing Network Gateways Page 5-3
AlphaNET Installation Guide, Revision 05
Look at the network example in the figure above; note there are network initialization files defining each
computer (node) on all four networks. However, the elements necessary for creating a gateway between
the networks are missing. Without the gateway defined, the communication between computers in our
network example would be very limited. Each computer would only be able to communicate with other
computers within its local network:
• Computer A would not be able to communicate with Computers B, C, D, and F.
• Computer B would not be able to communicate with Computers A, C, D, and F.
• Computer C would not be able to communicate with Computers A, B, D, and F.
• Computer D would not be able to communicate with Computers A, B, and C.
• Computer E is directly attached to all the computers, therefore it is able to communicate with
each computer on all four networks.
• Computer F would not be able to communicate with Computers A, B, and C.
By defining gateways, we can fully connect this network. To define a gateway, you create an
initialization file (filename.GIN) containing a
NETWORK= statement defining the network you wish to
make available, a
NAME= statement to assign a symbolic name, and a FORWARDTO= statement to
define the network address of the node to which to forward all traffic for the network being defined. Then
enter a NETINI statement processing that .GIN file in your system initialization command file. For
example:
NETINI SER001.GIN
To fully interconnect all six computers shown in the figure above, each of the computers would have to
define gateways as shown in the table below (in addition to defining the networks to which they are
physically connected):
The network initialization files (*.NIN) must be defined in your system initialization command file
before your gateway initialization files (*.GIN).