Appendix E: Understanding IP and IP addressing 147
The routed protocol of the architecture (usually the
The routing protocol distributes information on the availability or reachability of networks or subnetworks (also loosely referred to as wires). To choose the optimum path, the routing protocol uses a metric to rank the paths to the destination network. This information is compiled into a routing table or database. There are two main routing protocols found in TCP/IP networks: routing information protocol (RIP) and open shortest path first (OSPF). These protocols, along with other methods of defining routes are briefly described in "Protocols related to Internet Protocol" on page 160.
Planning overview
Integrating a SuperNode into the Ethernet network structure requires some planning. The process for this planning stage is summarized in the following steps:
1Map the networks to which the SuperNode connects through the EIU.
2Choose the IP addresses for the EIUs. Determine the optimum subnetwork masks, if necessary.
3Identify special requirements for the networks.
If there is only one EIU in the network, the planning stage is complete. However, if there are other routers, of any manufacture, included in the plans, three additional steps are needed:
1Select a routing protocol. In cases where the EIU is to be integrated into an existing network, choose the routing protocol to conform or interoperate with the existing network.
2Gather relevant information about the networks involved, including server addresses and special needs.
3If the network connects to other networks that are not under the control of the operating company, plan security firewalls to prevent unauthorized access to the network.
Mapping the network
It is very important to have a usable representation of the network before installing the EIU. If IP is already in use in the network, it may be a simple matter of a rough diagram showing the network numbers needed and the IP addresses assigned to the ports. Figure 26 on page 148 illustrates a simple network map.
