Hitachi GR2000 manual

When you replace the existing router (other than GR2000) with this router, pay attention to possible deviation of RIP-1 implementation. For example, the followin routers have different implementations of RIP-1: Hitachi’s NP200, NP150, NP100 NP120C, and Cisco Systems’ routers.

When an interface address is further divided into subnets, GR2000 does not crea natural mask route (network route for the subject interface). Instead, it creates a subnet route with broadcast connection and a host route with point-to-point connection. Since RIP-1 does not advertise a subnet route that exceeds the addressing boundary, aggregation specifying with the configuration definition is required on GR2000.

A different implementation of RIP-1 may automatically aggregate subnet routes t network route, and an aggregated route is usually not registered in the forwardin table. On GR2000, the aggregated route is by default registered in the forwarding table as the active route.

In order to attain compatible operation on GR2000 with such a device with differ RIP-1 implementation, the noinstall option setting is required for the aggregate definit in the configuration information. Figure 4-12 illustrates a sample network configuration requiring the noinstall option setting.