Information Technology Reference
In-Depth Information
Layer 3 Switching
in the Core
Core
Route Summarization
and Load Balancing
Layer 3
Routed
Layer 3 Boundary, Packet
Filtering, Policing, Aggregation
of Access
Distribution
Layer 2
Switched
Access
Layer 2 Switching
in Wiring Closet
Figure 2-2
Switched Hierarchical Design
Layer 3 Switching
in the Core
Core
Route Summarization
and Load Balancing
Layer 3 Boundary, Packet
Filtering, Policing
Distribution
Route Filtering Toward
Access Layer
Access
Layer 3
Routed
VLANs Local to
Wiring Closet
Layer 2
Switched
Figure 2-3
Routed Hierarchical Design
With VSS, the physical topology changes as each access switch has a single upstream dis-
tribution switch versus having two upstream distribution switches. VSS is configured only
on Cisco 6500 switches using the VSS Supervisor 720-10G. As shown in Figure 2-4, the
two switches are connected via a 10GE link called virtual switch link (VSL), which makes
them seem as a single switch. The key benefits of VSS include
Layer 3 switching can be used toward the access layer, enhancing nonstop communi-
cation.
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Scales system bandwidth up to 1.44 Tbps.
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