•The
Campus Enterprise Architecture is based on the local VLAN model wherein
users
of geographically common switches are grouped into a single VLAN, regardless of
the organizational function of the users.
•Local
VLANs are generally confined to a wiring closet, as shown in the figure, and
VLANs are local to one access switch which trunks to the distribution switch.
•If
users move from one location to another in the campus, their connection changes
to the new VLAN at the new physical location.
•In
the local VLAN model, Layer 2 switching is implemented at the access level and
routing is implemented at the distribution and core level, as shown in the
figure, to enable users to maintain access to the resources they need.
§Create
local VLANs with physical boundaries in mind rather than job functions of the
users.
§Local
VLANs exist between the access and distribution layers.
§Traffic
from a local VLAN is routed at the distribution and core levels.
§Switches
are configured in VTP transparent mode.
§Spanning
tree is used only to prevent inadvertent loops in the wiring closet.
§One
to three VLANs per access layer switch recommended.
