Alteon Application Switch Operating System Application Guide
Basic IP Routing
112
Document
ID:
RDWR-ALOS-V2900_AG1302
Figure 10 - Example Topology Migration, page 112
illustrates an example topology migration:
Figure 10: Example Topology Migration
In this example, a corporate campus has migrated from a router-centric topology to a faster, more
powerful, switch-based topology. The legacy of network growth and redesign has left the system
with a mix of illogically distributed subnets.
This is a situation that switching alone cannot normalize. 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 the router
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, competition for access to
common server pools on different subnets still burdens the routers.
This problem is solved by using Alteon with built-in IP routing capabilities. Cross-subnet LAN traffic
can now be routed within Alteon with wire speed Layer 2 switching performance. This not only eases
the load on the router but saves the network administrators from reconfiguring each and every end-
station with new IP addresses.
