Web OS 10.0 Application GuideChapter 1: Basic IP Routing n 29212777-A, February 2002For example, consider the following topology migration:Figure 1-1 The Router Legacy NetworkIn this example, a corporate campus has migrated from a router-centric topology to a faster,more powerful, switch-based topology. As is often the case, the legacy of network growth andredesign has left the system with a mix of illogically distributed subnets.This is a situation that switching alone cannot cure. Instead, the router is flooded with cross-subnet communication. This compromises efficiency in two ways: Routers can be slower than switches. The cross-subnet side trip from the switch to therouter and back again adds two hops for the data, slowing throughput considerably. Traffic to the router increases, increasing congestion.Even if every end-station could be moved to better logical subnets (a daunting task), competi-tion for access to common server pools on different subnets still burdens the routers.This problem is solved by using Alteon Web switches with built-in IP routing capabilities.Cross-subnet LAN traffic can now be routed within the Web switches with wire speed Layer 2switching performance. This not only eases the load on the router but saves the networkadministrators from reconfiguring each and every end-station with new IP addresses.Admin/SalesServerSubnetRouterSwitchStaff/Eng2SwitchEng/Staff2/SalesSwitchFDDIInternetWeb SwitchAdmin. SubnetServerSubnetHubStaff SubnetHubEng. SubnetHubInternetFDDI Router
