The distribution layer of the network
divides the access and core layers and helps to define and
differentiate the core. This layer provides a boundary definition
and is the place at which packet manipulation takes place. In the
campus environment, the distribution layer can include several
functions, such as the following:
- Address or area aggregation
- Departmental or workgroup access
- Broadcast/multicast domain
definition
- VLAN routing
- Any media transitions that need to
occur
- Security
In the noncampus environment, the
distribution layer can be a redistribution point between routing
domains or the demarcation between static and dynamic routing
protocols. It can also be the point at which remote sites access the
corporate network. The distribution layer can be summarized as the
layer that provides policy-based connectivity.
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