TP-Link T2600G-18TSTL-SG3216 T2600G-18TSUN V1 Configuration Guide - Page 301

Configuring Private VLAN Overview Note： T2600G-18TS doesn't support the function of Configuring Private VLAN. 1 Overview Common large networks such as ISP networks generally isolate users by VLAN. However, with the increasing number of users, upper-layer devices have to create large amount of VLANs to manage all the users. According to IEEE 802.1Q protocol, each upperlayer device can create no more than 4094 VLANs, which means upper-layer devices in backbone networks will face shortage of VLANs. By creating primary VLAN and secondary VLAN, private VLAN is an effective solution to this problem. Based on 802.1Q VLAN, private VLAN pairs a secondary VLAN with a primary VLAN. A primary VLAN can pair with more than one secondary VLAN to compose several private VLANs. In a private VLAN, Layer 2 isolation can be achieved between end users with secondary VLANs, while upper-layer devices only need to recognize primary VLANs, which solves the problem of VLAN shortage. Meanwhile, private VLAN resolves the conflicts triggered when users' need of VLANs is different from what the ISP can provide. The network models of traditional VLAN and private VLAN are shown in Figure 1-1 and Figure 1-2 respectively. In the network model of traditional VLAN, isolation between users is achieved by creating VLAN2, VLAN3 and VLAN4. In this case, the upper-layer device, Switch A, needs to recognize 3 VLANs including VLAN2, VLAN3 and VLAN4. Figure 1-1 Topology of Traditional VLAN Switch A Switch B VLAN2 VLAN3 VLAN4 Configuration Guide 271