Specifications

Network Redundancy
PlantScape Server and Client Configuration Guide 303
Network Redundancy
Two forms of network redundancy, both optional, are available for PlantScape
servers and Stations:
• Ability for a pair of servers to perform database synchronization and other
redundancy functions over a dual network (highly recommended to avoid a
single point of failure)
• Ability of Stations to connect to non-redundant and redundant servers via
dual networks
These capabilities are independent of each other and are configured separately.
However, they have the same requirements for network configuration, which are
described in this section. For dual network configuration procedures, see the
Installation Guide.
Network Configuration Requirements
• Two networks that have distinct IP Subnet/Network IDs. The network
redundancy scheme requires two NICs in the server or servers, and also in
any Stations that participate in the dual network scheme. In the sample
diagram and for this discussion, these networks are called X and Y.
• Two separate IP Networks (or subnets). One NIC in each participating
server or Station must be connected to one cable/hub. The other NIC in
each participating server or Station must be connected to the other
cable/hub.
• All NICs connected to the first cable/hub have the same
network/subnetwork ID, X.
• All NICs connected to the second cable/hub have the same
network/subnetwork ID, Y.
• All IP addresses on either network must have the form X.host or Y.host. This
is a consequence of the required NIC connections. If you are not careful to
ensure this, you can create some very difficult situations to debug.
The IP address assigned to NIC A in a node has no relationship to the IP address
assigned to NIC B in the same node, but both addresses must comply with these
network and subnetting requirements. If you need to use certain IP addresses
because of their availability, you must ensure that they are on the correct subnet.
plscpcg.book Page 303 Monday, May 28, 2001 10:11 AM