S Layer 2 Managed Switch User Manual
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20
Data packet will be forwarding normally only source MAC, VLAN ID are both matching. As the figure showing, if data packet
that host A send carries VLAN TAG and VLAN ID is 2, even source MAC address are compatible with the binding MAC address,
but since it is not compatible with VLAN ID 1 that bound with port 10 of
S
, then this packet will be dropped by the
switch and it can not visit WEB.
If there is a port does not bind any MAC address in
S
, this port will not check source MAC address of flow-in data
packet. If ever this port binds any MAC address, switch will limit data packet flow to this port. Data packet will be allowed to
go through only source MAC address follows the rules.
Notice: Based on port,
S
’s MAC address binding function contradict with 802.1X authentication function. If some
port is configured with 802.1x authentication function, this port can not be configured with MAC address binding. Meanwhile
if some port is bound with MAC address, this port can not configured 802.1x authentication function.
Notice: Only 1-24 ports of
S
support MAC address binding. 25 and 26
ports do not support MAC address binding.
4.3.6 ARP table of switch
S
maintenance an ARP address resolution table. You can realize all hosts’ IP addresses correspond with MAC
addresses that go through
S
via this ARP table.
4.4 VLAN management
VLAN (Virtual Local Area Network) can limit data exchange in each virtual network thus decrease transmission of broadcast
package in whole network and increase network transmission efficiency. Meanwhile each virtual network can not
communicate directly but must forward data via router. This helps isolating ports, increasing network safety and making it
possible for high-grade safety control. VLAN can be widely applied. All situations that requires frequently data exchanging and
safe network are suitable e.g. 1. In intelligent village, campus, enterprise etc, utilize VLAN function in order to make each
VLAN station can not communicate each other. This ensures network safety control; 2. In big internet café, big & medium
enterprise, utilizing VLAN can significantly decrease non-necessary data exchange, eliminate broadcast storm, increase
network transmission capability. Each network section can use the same network equipments through network division. It
not only reduces expenditure of network hardware, but also in favor of equipment transmission and decreasing network
connection cost.
S
supports three VLAN modes: IEEE 802.1Q VLAN, Port VLAN and Protection VLAN.
(Notice: You can only adopt one
VLAN mode in the same time. When you modify VLAN mode, all relative configuration will be recovered to initial value).
Below is the introduction to these three VLAN modes:
4.4.1 IEEE802.1Q Tag VLAN
At the beginning of application of VLAN, each manufacturer’s switch can not identify and be compatible with each other due
to lack of united standard. After new VLAN standard of IEEE802.1Q was constituted, devices that come from different
manufacturer can be used in the same network. Switches which follow IEEE802.1Q standard can exchange VLAN message and
communicate each other.
IEEE802.1Q standard defines a new frame format. It adds a Tag Header after source address of standard Ethernet frame.
Shown as below:
