Category Archives: Network Switch

What Is IGMP Snooping and IGMP Snooping Switch?

IGMP snooping switches are gradually entering the core of the network. Maybe some people are still not familiar with the fresh terms such as IGMP snooping, IGMP snooping switch, etc. What is IGMP snooping? What is IGMP snooping switch? All tells in this post.

What Is IGMP Snooping?

IGMP snooping, short for Internet Group Management Protocol Snooping, is a multicast constraint mechanism that runs on layer 2 devices to manage and control multicast groups. As shown in the following figure, this Layer 2 device is usually a data switch. The Layer 2 device (switch) running IGMP snooping analyzes the received IGMP messages and establishes a mapping relationship between the Layer 3 (router) and receivers. Then the layer 2 device (switch) forwards the multicast data according to the mapping relationship. When the layer 2 device (switch) is not running IGMP snooping, the multicast data is broadcast on the second layer. After the layer 2 device (switch) runs IGMP snooping, the multicast data of the multicast group is not broadcast on the second layer but among the known receivers on the second layer.

IGMP Snooping

Enable IGMP Snooping: Before and After

Types of IGMP Snooping

There are two types of IGMP snooping. One is passive and the other is active. The passive mode only parses multicast packets and does not filter packets. The active mode filters out multicast packets that are meaningless to the router. For example, two receivers under the switch using the passive mode are added to the same group, so that there is an entry in the router above the switch. If a receiver wants to leave the group, it sends a leave message to the router. However, even if the router receives the leave message, it does not delete the entry because there is another receiver in the multicast group. Different from the passive mode, the active mode enables the switch to filter out such packets.

What Is IGMP Snooping Switch?

A data switch with IGMP snooping is called an IGMP snooping switch. This kind switch can parse the IGMP packets passing through it and establish a multicast forwarding mapping relationship. In this way, the switch can forward multicast data according to the multicast mapping relationship. If this function is disabled, the switch can only broadcast multicast data. The practical application of IGMP snooping switch is to reduce the processing load caused by receivers on the network receiving unnecessary multicast packets. Most IGMP snooping switches use the active mode, so they can snoop the IGMP messages and leave messages and forward them only when necessary to the connected IGMP routers.


Today, IGMP snooping has become very common and advanced, and the current network supports multicast transmission. Besides, for the convenience and saving the load of the server, using the IGMP snooping switch is required. Although there are some shortcomings, the future of the this kind switch is promised. FS.COM can provide IGMP snooping 10Gbe switch. In addition to this, we also offer the Gigabit Ethernet switch for various ports. If you have any questions or needs about these, please visit

Why Choose 10 Gigabit ISCSI Switch for SAN?

With the development of technology, many users are considering upgrading to 10 Gigabit Ethernet switch. Of course, when it comes to the edges of the fiber switch, the obvious advantage of the Gigabit switch is the speed. The Gigabit Ethernet and 10GbE switch can also bring other advantages, such as reducing cabling and bottlenecks. In addition, another important advantage is iSCSI support. This involves our theme today: 10G iSCSI switch for SAN, which is highly scalable because its capacity can be added as required.

Ethernet Switches

What is the SAN (Storage Area Network)?

The SAN is a dedicated high-speed network or subnet that connects shared pools of multiple storage devices to multiple servers. The SAN is usually assembled through three main components: cabling, host bus adapters (HBAs), and switches connected to storage arrays and servers. Now, let’s focus on the SAN switch. What need SAN switches to do is to move storage traffic. SAN switches are usually FC switches, which are compatible with many FC protocols based on SAN. At the same time, SAN switches can also be based on Ethernet. Such switches should only process traffic on IP SAN to maintain predictable performance. Ethernet switches provide traffic for IP addresses. They treat iSCSI storage targets as IP addresses. These Ethernet switches are what we call iSCSI switches.

Those people who focus on 10G devices have a common misconception that only an expensive and difficult-to-maintain fiber connect network is needed to effectively connect distributed storage SAN. While the FC has its advantages, the iSCSI switch can run economically on your existing Ethernet hardware (although the dedicated hardware is better) and works well on a 10G network.

Understanding the ISCSI Switch

When we need to build our SANs or iSCSI network, we usually heard of DELL iSCSI switch, HP iSCSI switch and so on. However, what is the iSCSI switch? The iSCSI switch is a device that processes and channels data between the iSCSI initiator and the target on a storage device. ISCSI traffic is usually high speed and high capacity, and it needs to be provided with minimal delay. Unlike dedicated FC SAN switches, iSCSI switches are standard Ethernet network switches and can be used for iSCSI traffic optimization. ISCSI switches provide reliability while enhancing network control and supporting quality of service.

10G ISCSI Switch

Figure: 10G ISCSI Switch

The Reason Why Choose 10G ISCSI Switches for SAN

Then, why we choose 10G iSCSI switches for SAN? There are three main reasons, they can be concluded as follows:

  • Flow control: building the SAN by using 10G iSCSI switches can help the host avoid being overwhelmed by the high traffic associated with iSCSI storage through allowing the host to control the rate at which data is received, and use flow control. Traffic control can also help prevent packet loss and avoid increased delays in iSCSI storage networks.
  • Jumbo frame: the high payload of jumbo frames can be processed by providing fewer frames to the switch, thereby improving the efficiency of data transmission. This can improve 10G iSCSI performance, but using jumbo frames may cost more. Basically, the better the iSCSI switch is, the better your SAN will be.
  • Link aggregation: also known as port trunking, this feature combines switch ports into higher bandwidth trunks to increase throughput and create redundancy. This is significant for you to build your SAN.


The world’s needs for data is growing, and nothing seems to be able to solve this problem. The video is becoming more and more high-definition, VR application is more and more used, and even the daily web pages are upgraded. If your business is already feeling the pressure of a data bottleneck, upgrading to a 10G iSCSI switch will put you back on the fast lane.