3com 8807 User Guide

Isolate-user-VLAN can save the VLAN resource in a network. It adopts the 
two-level VLAN architecture. One level is isolate-user-VLAN level, and the other is 
Secondary VLAN level, as shown in Figure 12.

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An isolate-user-VLAN corresponds to multiple Secondary VLANs. It contains all 
the ports and upstream ports of the corresponding Secondary VLANs. In this 
way, a switch that is of upper level only needs recognizing the 
isolate-user-VLANs of the downstream switch instead of the Secondary VLANs, 
thereby streamlining the configuration and saving the VLAN source.

■

You can use isolate-user-VLAN to implement the isolation of the Layer-2 
packets by assigning a Secondary VLAN for each user, with each of the 
Secondary VLANs containing the ports and the upstream ports connected to 
the user. You can configure the ports connected to different users to be of the 
same Secondary VLAN to enable these users to communicate with each other 
on Layer 2. 

Figure 12   Isolate-user-VLANs and Secondary VLANs

(Secondary VLAN

)

VLAN 4

VLAN 6

VLAN 3

VLAN 2

(isolate-user-vlan)

(Secondary VLAN

)

(Secondary VLAN

) (Secondary VLAN

)

VLAN 3

VLAN 5

(isolate-user-vlan)

(Secondary VLAN

)

VLAN 4

VLAN 6

VLAN 3

VLAN 2

(isolate-user-vlan)

(Secondary VLAN

)

(Secondary VLAN

) (Secondary VLAN

)

VLAN 3

VLAN 5

(isolate-user-vlan)

VLAN 6

VLAN 3

VLAN 2

(isolate-user-vlan)

(Secondary VLAN

)

(Secondary VLAN

) (Secondary VLAN

)

VLAN 3

VLAN 5

(isolate-user-vlan)

Table 47   Isolate-user-VLAN configuration tasks

Configure an isolate-user-VLAN 

Required 

Refer to section “Product Overview” 

Configure Secondary VLAN 

Required 

Refer to section “Configuring a 
Secondary VLAN” 

Configure the mapping relationship 
between isolate-user-VLANs and 
Secondary VLANs 

Required 

Refer to section “Mapping an 
isolate-user-vlan to Secondary VLANs”