Tp-Link TL-SG1016DE V2 Configuration Guide онлайн [33/49] 394948

(2) Network security is improved. VLANs cannot communicate with one another directly.

That is, a host in a VLAN cannot access resources in another VLAN directly, unless

routers or Layer 3 switches are used.

(3) Network configuration workload for the host is reduced. VLAN can be used to group

specific hosts. When the physical position of a host changes within the range of the

VLAN, you do not need to change its network configuration.

There are 3 types of VLAN modes supported in the switch:

1. MTU VLAN

MTU VLAN (Multi-Tenant Unit VLAN) defines an uplink port which will build up several VLANs

with each of the other ports. Each VLAN contains two ports, the uplink port and one of the

other ports in the switch, so the uplink port can communicate with any other port but other

ports cannot communicate with each other.

2. Port Based VLAN

VLANs are divided based on ports. By default, the Port Based VLAN is enabled.

3. 802.1Q VLAN

The IEEE 802.1Q protocol defines a new format of the frame; it adds a Tag header in the

original Ethernet frame, as follows:

Figure 6-2 IEEE 802.1Q Frame

VLAN tags in the packets are necessary for the switch to identify packets of different VLANs.

The switch works at the data link layer in OSI model and it can identify the data link layer

encapsulation of the packet only, so you can add the VLAN tag field into the data link layer

encapsulation for identification.

IEEE 802.1Q Tag VLAN is divided by VLAN ID (VID). On receiving a frame, the switch checks the

VID in the Tag header of the frame to decide which VLAN it belongs to. If the receiving frame

doesn’t contain the Tag header, the switch will assign a Tag to the frame, using the PVID of the

port as its VID.