Multi-layer switching tutorial

How does layer 3's SWITCHING work? Process and principle ??
L2 Switching
Hardware-based bridging, ASIC Technology
Main design objective: Wire-speed performance
High-speed scalability, Low latency, MAC, Low cost
Provides administrators with the ability to increase or decrease bandwidth without adding unnecessary complexity to the network.
Working group connectivity and network segmentation are two major uses of L2 switches.
L2 switching Defects
Broadcast still affects the End Node
Reducing the number of hosts in each CIDR Block leads to a flat structure of more CIDR blocks
Restrictions on slow convergence and link congestion of Spanning Tree Protocols
L3 switch completes the following work
Determine the forwarding path based on the L3 Information
Verify the integrity of the L3 Header
Verify the validity period of the data packet and update it accordingly.
Process and respond to any option Information
Update Forwarding statistics in MIB
Implement Security Control
The difference between L3 switching and routing: the microprocessor-based engine on the Router performs Packet Exchange, and the L3 switch performs Packet Exchange through hardware. Routing, such as a single mailbox, can process multiple processes at the same time.
L3 devices include routers and switches. Two basic functions are available: Selecting and exchanging L2 information and reducing TTL.
Catalyst Switch product with two major L3 switching implementation solutions: multilayer switching and CEF
GSR performs L3 line rate switching through the switching matrix. The Catalyst series multi-layer switches implement L3 switching through ASIC.
High-performance packet switching, High-speed scalability, Low latency, Lower per-port cost, Flow accounting, Security, QoS
L4 Switching

It can be defined as: not only the MAC/IP address is taken into account, but also the ability to make forwarding decisions based on L4 parameters.
Sometimes called Layer 3-plus switching
The CISCO router can control traffic based on L4 information. The ACL and NetFlow provide L4 statistics.
When the L4 function is executed, the switch/router reads the TCP/UDP field to determine the information type carried by the data packet. The network administrator can set the switch to prioritize the data stream based on the application and define the end-to-end QoS.
L4 switching is required if the policy requires refined Traffic Control Based on the application or traffic statistics based on the application.
L4 switches need to identify and store a large number of forwarding entries, so the forwarding table size should be proportional to the network size.