Chapter 2: EIU messaging protocols 57
•the IP address class
•the IP address subnet size based on number of subnets and the maximum number of hosts per subnet (also, consider future expansion of the network)
•the IP addresses for HUBs and routers
•the dynamic routing strategy (only RIP is supported on the EIU)
•network security (if the network is connected to public network such as the Internet, security consideration is vital)
Routing
The IP is a network layer protocol using the ISO
The IP routing algorithm must route messages from SuperNode hosts to the following:
•internal SuperNode SOS and
•
When the destination host is not attached to the SuperNode network2, IP must route messages to a neighboring IP router. In this way, IP forwards route messages toward the final destination. SuperNode connectivity to external hosts is possible through EIUs. The EIU, in this context, is referred to as an IP router. Generally, IP routers have more than one network interface (the network interface is defined as the node’s connectivity to the underlying network, whether it is Ethernet or FTS), to allow IP messages to pass from one network to another. The IP router may also provide connectivity to networks with distinct architectures. The EIU is one such IP router.
The EIU acts as the IP router between the SuperNode hosts (through the FTS network interface) and the Ethernet LAN (through the Ethernet interface). The EIU receives and forwards messages between the Ethernet LAN and the SuperNode hosts. Some unique characteristics of SuperNode IP routing are as follows:
•IP messages destined from one SuperNode host to another SuperNode host within same SuperNode are sent directly without any intermediate nodes as routers or gateways.
•IP messages destined to hosts on the LAN are sent through one of the available (in service) EIU IP routers connected to that LAN.
2. A SuperNode network is the network of SuperNode hosts reachable through FTS.
