Elimination of Peering Problems

Elimination of Peering Problems
Because routing is typically performed in the distribution layer devices, each distribution layer
device must have “reachability” information about each of the other distribution layer devices.
These layer 3 devices use routing protocols to maintain the state and reachability information
about neighbor routers. This means that each distribution device becomes a peer with every
other distribution layer device, and scalability becomes an issue because every device has to keep
information for every other device.
If your layer 3 devices are located in the core, you can create a hierarchy, and the distribution
layer devices will no longer be peers to each other’s distribution device. This is typical in an environment
in which there are more than 100 switch blocks.