Company XYZ, a global content provider, owns data centers on different continents. Their data center design involves a standard three-layer design with a Layer3-only core. HSRP is used as the FHRP. They require VLAN extension across access switches in all data centers, and they plan to purchase a Layer 2 interconnection between two of their data centers in Europe. In the absence of other business or technical constraints, which termination point is optimal for theLayer 2interconnection?
- at the core layer, to offer the possibility to isolate STP domains
- at the aggregation layer because it is the Layer 2 to Layer 3 demarcation point
- at the access layer because the STP root bridge does not need to align with the HSRP active node
- at the core layer because all external connections must terminate there for security reasons
Answer(s): B
Explanation:
The aggregation layer is the ideal termination point for the Layer 2 interconnection because it is the Layer 2 to Layer 3 demarcation point. This means that the Layer 2 interconnection can be isolated from the core layer, which can help to improve security and performance.
The other options are not as optimal. Option A, at the core layer, to offer the possibility to isolate STP domains, is not as optimal because it would require the Layer 2 interconnection to terminate at the core layer, which can increase latency and complexity. Option C, at the access layer because the STP root bridge does not need to align with the HSRP active node, is not as optimal because it would not allow for the isolation of STP domains. Option D, at the core layer because all external connections must terminate there for security reasons, is not as optimal because it is not necessary to terminate all external connections at the core layer.