Best practices for identifying layer-3 switch devices

Currently, most layer-3 switch devices in the market support link aggregation and Spanning Tree Protocols, which can effectively improve the overall network performance and meet more user needs. With the gradual development of network applications, telecom-grade switches, especially layer-3 switches, have become the focus of competition in today's market. However, how do users discover products that meet their application characteristics in the case of L3 switch devices with different functions and a wide variety of features? This not only requires users to start with the traditional switch evaluation indicators, consider the product cost effectiveness, but also pay special attention to whether the product can provide support for some of the latest features with high value-added.

Generally speaking, evaluating the advantages and disadvantages of a vswitch should begin with three aspects: overall architecture, performance, and function. The overall architecture refers to the value of basic performance parameters such as the port density, the maximum rate supported by the port, and the switching capacity of a layer-3 Switch. This allows you to determine the location and grade of the device.

In addition to the basic RFC2544 standard, throughput, latency, and packet loss rate, the performance of a vswitch also increases with the increase of user services and application development, such as the number of MAC addresses, route table capacity (layer-3 Switch), number of ACLs, LSP capacity, and number of VPN supported. Take the number of MAC addresses as an example. The number of MAC addresses is the maximum number of MAC addresses that can be stored in the MAC address table of the vswitch. The more MAC addresses are supported, the higher the data forwarding rate.

Function is the most direct indicator

For general access layer switches, simple QoS Assurance, security mechanisms, support for network management policies, spanning tree protocols, and VLANs are essential functions. However, if you carefully analyze them, some features can be further subdivided under a simple representation, which is the main cause of product Differences and an important way to reflect the added value of products.

Application-level QoS Assurance

In order to provide more flexibility for users in practical applications, the QoS policy of the switch must support multi-level packet priority settings, which can be set for MAC addresses, VLANs, IP addresses, and ports respectively. At the same time, the layer-3 switch must have good congestion control and traffic limit capabilities, support Diffserv Differentiated Services, and intelligently differentiate different application flows based on the source/Target MAC/IP addresses, meet the needs of real-time multimedia applications. Although some vswitches on the market also claim to have QoS guarantee, they only support single-level priority settings, which brings a lot of inconvenience to users' actual applications.

VLAN support

VLAN is a virtual LAN. By dividing a LAN into virtual network vlan cidr blocks, network management and network security can be enhanced to control unnecessary data broadcast, working Groups in the network can break through the geographic location restrictions in the shared network and divide subnets based on the management function. Vswitches of different manufacturers have different support capabilities for VLANs, and the number of supported VLANs varies.

Network management functions

Through the network management function, you can use management software to manage and configure vswitches, such as Web browsers, Telnet, SNMP, and RMON. Generally, vswitch vendors provide management software or third-party management software to remotely manage vswitches. Generally, a layer-3 Switch meets the requirements of the SNMPMIBI/MIBII statistical management function, and supports policies such as configuration management, service quality management, and alarm management, the complex gigabit switches support the active RMON monitoring function by adding the built-in RMON group (mini-RMON. This policy is supported by the ISCOM2826 vswitch. In the SNMP network management mode, RCNVIEW, a comprehensive network management platform of the company, can be managed.

Link Aggregation

Link aggregation makes the link bandwidth between vswitches and servers very scalable. For example, two, three, and four Gigabit Links can be bound together, multiply the bandwidth of the link. Link aggregation technology can achieve load balancing of different ports, and also backup each other to ensure link redundancy. In some Gigabit Ethernet switches, a maximum of four link aggregation groups are supported, and each group has a maximum of four ports. Both the Spanning Tree Protocol and link aggregation can ensure the redundancy of a network. Set redundant links in a network and use the Spanning Tree Protocol to block the backup link. Logically, no loops are formed. In the event of a fault, the backup link is enabled. The three layer-3 switch devices we recommend this time provide effective support for Link aggregation and Spanning Tree Protocols. GreenNet's TiNetS3526 not only supports binding eight 10/100 Base-T adaptive ports, it also supports aggregation of Gigabit ports.

Support VRRP Protocol

VRRP (virtual router redundancy protocol) is a solution to ensure network reliability. In this protocol, the default gateway (DefaultGateway) of the terminal IP device on the shared multi-access media is backed up redundant, so that when one of the three-tier switch devices goes down, the backup device takes over the forwarding in a timely manner and provides transparent switching to users, improving the network service quality. VRRP is similar to Cisco's HSRP Protocol, except that HSRP is private to Cisco. Currently, mainstream switch manufacturers have supported VRRP in their products, but it still takes a few days to widely use VRRP.