What is the difference between L3 access switch and L3 aggregation switch？

Layer 3 Access Switches:
1. Location: Located at the edge of the network.
2. Functionality:
￮ Provides connectivity for end-user devices such as computers, printers, and servers.
￮ Performs basic routing functions to forward traffic to the correct subnet or VLAN.
3. Features:
￮ Supports features like Quality of Service (QoS), VLANs, and security policies.
￮ May have fewer ports compared to aggregation switches.
￮ Often includes wireless access points or supports connections to them.
4. Purpose:
￮ Serves as the first point of contact for user devices.
￮ Applies security policies, such as access control lists (ACLs).
Layer 3 Aggregation Switches:
1. Location: Positioned above the access layer, typically closer to the core of the network.
2. Functionality:
￮ Aggregates traffic from multiple access switches.
￮ Performs more complex routing decisions and inter-VLAN routing.
3. Features:
￮ Offers advanced routing protocols like OSPF, BGP, and VRRP.
￮ Can support a higher density of ports and higher bandwidth capabilities.
￮ Includes robust QoS mechanisms and policy enforcement.
4. Purpose:
￮ Consolidates and forwards traffic to the core layer or other aggregation layers.
￮ Provides scalability and redundancy in network design.
In summary, Layer 3 access switches are responsible for connecting end-user devices and applying initial security and policy enforcement, while Layer 3 aggregation switches aggregate traffic from multiple access switches and perform more sophisticated routing tasks before forwarding it to the core network.