Explanation/Reference:
Explanation:
User access is primarily layer 2 in nature, layer 2 clustering is possible only in layer 2 Here is the
Explanation: from the Cisco press CCDA certification guide Figure 4-8. Enterprise Data Center
Infrastructure Overview

Defining the DC Access Layer
The data center access layer's main purpose is to provide Layer 2 and Layer 3 physical port density for
various servers in the data center. In addition, data center access layer switches provide high-
performance, low-latency switching and can support a mix of oversubscription requirements. Both Layer 2
and Layer 3 access (also called routed access) designs are available, but most data center access layers
are built using Layer 2 connectivity. The Layer 2 access design uses VLAN trunks upstream, which allows
data center aggregation services to be shared across the same VLAN and across multiple switches. Other
advantages of Layer 2 access are support for NIC teaming and server clustering that requires network
connections to be Layer 2 adjacent or on the same VLAN with one another.
CCDA 640-864 Official Certification Guide Fourth Edition, Chapter 4