In-depth analysis of the powerful functions of Gigabit Ethernet Switches

In-depth analysis of the powerful functions of the Gigabit Ethernet switch, this evaluation is mainly to measure the performance of the Gigabit Ethernet switch, another layer-3 Gigabit Ethernet switch is 3Com4900, different subnets are included to test their performance.

Powerful functions

Our evaluation is mainly to measure the performance of the Gigabit Ethernet switch, and we also consider the features of the Gigabit Ethernet switch through configuration and validation tests. Two of our Gigabit Ethernet switches are capable of forwarding on the third layer.

Digital China D-Link DGS-3308TG is one of them, we set their eight ports to different VLANs, into different subnets to test its performance, quite good. As a fixed and modular Gigabit Ethernet switch, it also supports more complex routing protocols such as OSPF.

Another layer-3 Gigabit Ethernet switch is 3Com4900. After the software is upgraded, It is a layer-3, layer-4 Gigabit Ethernet switch. We tested its L3 performance. In layer-4 mode, it can identify application streams based on TCP port numbers and assign priority to different application streams. For example, assign a high priority to the packets of an SNMP application to ensure network management is feasible. Set a higher priority for an application whose port number is 80.

In fact, to ensure high network performance, these Gigabit Ethernet switches that can be managed support restrictions on broadcast storms. At the same time, all the Gigabit Ethernet switches that are sent to test support the traffic control protocol of X 3 to ensure that, in the case of congestion, they negotiate with other network devices to reduce the transmission speed of frames, ease network congestion. For Gigabit Ethernet switches that support copper interfaces, they also support traffic control in the back pressure mode of Mbit/s half duplex.

More Gigabit Ethernet switches provide IEEE 802.1p priority control, while 3Com4900 and shenzhou.com-Link DGS-3308TG's Gigabit Ethernet switches provide 4 priority queues per port, this is the most popular test product. The DGS-3308TG of digital D-Link can also assign priority based on the source and destination addresses of data frames.

We found that many Gigabit Ethernet switches combine the 802.1p priority with the 802.1Q setting to provide VLAN service quality control. In fact, in addition to ensuring security, VLANs can also improve network performance by limiting broadcast domains.

All Gigabit Ethernet Switches of the network type support VLAN 802.1Q. The digital D-Link DGS-3308TG switch supports up to 2048 VLANs. 802.1Q is tagged on an Ethernet frame, allowing a VLAN to span multiple Gigabit Ethernet switches, and a port in a Gigabit Ethernet switch belongs to multiple VLANs at the same time. All these vswitches support GVRP and GMRP, allowing the host to automatically register to the VLAN and multicast group of the network.

Link aggregation can make the link bandwidth between switches and Gigabit Ethernet switches and servers very scalable. For example, we can bind two, three, and four Gigabit Links together, multiply the bandwidth of the link. The link aggregation technology can achieve load balancing of different ports, while also ensuring link redundancy.

These Gigabit Ethernet switches support up to four link aggregation groups and each group has up to four ports. Generally, when link aggregation is set, we can see which ports belong to one switching chip. Cross-chip settings are not allowed for half of link aggregation.

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 without forming a loop logically. If a fault occurs, the backup link is enabled. However, the Spanning Tree Protocol takes too long to compute. IEEE is developing a new protocol, which is yuan.

The 3Com Gigabit Ethernet switch has an elastic link setting option. Assume that the two links are set to an elastic link group. When one link is disconnected, the Gigabit Ethernet switch will quickly start another link, which is more efficient than the spanning tree algorithm. It is said that the switch can be completed within one second.

The security of networks is becoming more and more important. ge Ethernet switches can isolate illegal customers from the network at the underlying layer. All the vswitches that can be managed support the MAC address filtering function. You can also bind the MAC address with a fixed port and the VLAN. The 3Com and Digital China D-Link vswitches also support higher-level access list control.

In the face of more and more multicast applications, network-managed Gigabit Ethernet switches support IP multicast. Generally, they support IGMP (InternetGroupManagementProtocol). The switch can intelligently forward IGMP and multicast data packets, instead of broadcasting these packets to all ports.

IGMP probe IGMPSnooping) enables the Gigabit Ethernet switch to read IGMP data packets before forwarding data packets to learn which port is a multicast member ). 3Com4900 and digital shenzhoud-Link DGS-3308TG switches support layer-3 switching, with stronger support for IP multicast.