Four features of a layer-3 Switch

Before learning about the features of a layer-3 Switch in an Internet cafe, let's take a look at what layer-3 switch is?

Traditional switches work at the Layer 2 data link layer of the layer 7 network model and can only identify MAC addresses (hardware addresses of network device ports ). Layer-3 switching means that network devices can identify layer-3 network information (IP addresses) and use this information for fast data exchange.

The layer-3 switch can implement the internet cafe functions that the original router can complete, while the delay in data forwarding processing is far lower than that of the Internet cafe router, which can achieve the efficiency of the second layer switch.

The layer-3 Switch generates a ing table between the MAC address and IP address after the first new packet is forwarded. When a packet with the same address information passes through again, that is, based on this table, forwarding is directly completed on the second layer, that is, "one route, multiple exchanges", which effectively improves the efficiency of data packet forwarding. Therefore, it can be said that it is a combination of the advantages of layer-3 routing and layer-2 switching.

Three-tier switch features of Internet cafes:

1. Improve Security

In Internet cafes, for the sake of security, data packets must be filtered according to many rules to ensure that only compliant data packets can pass through the layer-3 switch. Layer-3 switches support internal hardware filters to filter all data packets without compromising system performance, in addition, data packets can be filtered based on any content from Layer 2 to Layer 7.

2. Support for Trunk Protocol

In applications, there are often cases where Ethernet switches are connected to each other or when Ethernet switches are interconnected with servers. A single connection used for interconnection often becomes a network bottleneck. The Trunk technology can be used to logically consider the Ethernet connection lines of several identical source switches and destination switches as one connection line. This not only ensures that no loop occurs in the LAN, but also effectively increases the connection bandwidth. The L3 switches with good performance fully support the Trunk protocol, and some support eight groups of trunks, which can effectively solve the connection bandwidth problem in the enterprise LAN.

3. Act as the backbone switch

Layer-3 switches are generally used as backbone switches and server group switches of the network, and can also be used as network node switches. In a network that works with other Ethernet switches, network administrators can build a seamless 10/100/Mbps Ethernet Switching System to provide unified network services for the entire information system. Such a network system has a simple structure and features such as scalability and policy-based QoS service.

Layer-3 switches provide QoS Services for networks, including priority management, bandwidth management, and VLAN switching. Policy-based QoS allows the network administrator to allocate bandwidth to different types of network traffic, including TCP/UDP sessions, by priority, without any loss of switching performance.

Due to application requirements, most of the backbone switches are Ge switches. Currently, most of the layer-3 switches are Ge switches. The 10/100 Mbps adaptive port and GE port can be provided to connect copper wires, you can also connect to the optical fiber and provide a high-performance backplane channel. The organic cabinet type of such switches can also be stacked and can be selected based on different situations.

4. Implement multicast and self-learning

In addition to the dynamic routing protocol RIP and OSPF, some third-level multicast protocols can also be implemented based on the standard multicast protocol to meet the increasingly popular requirements for Multi-Point multicast, for example, the distance vector Multicast Routing Protocol (DVMRP ).

The three-tier switch of an internet cafe also supports self-learning. It can automatically discover the ing between the host IP address and the connection port without using any routing protocol. Once a vswitch is connected to the network, it continuously learns the IP address and subnet mask information of all connected hosts by listening to ARP, RIP, and ICMP packets. Based on the learned information, the switch establishes and maintains the routing information in the route table and automatically provides routing services for all IP data packets.

As for the current situation, three-layer Switches of Internet cafes are gaining momentum, and the third-layer switches will dominate the LAN in the future.