ZyXEL ES-3148 Guida Utente

Chapter 8 VLAN

ES-3148 User’s Guide

Subnet based VLANs allow you to group traffic into logical VLANs based on the source IP 
subnet you specify. When a frame is received on a port, the Switch checks if a tag is added 
already and the IP subnet it came from. The untagged packets from the same IP subnet are then 
placed in the same subnet based VLAN. One advantage of using subnet based VLANs is that 
priority can be assigned to traffic from the same IP subnet.
For example, an ISP (Internet Services Provider) may divide different types of services it 
provides to customers into different IP subnets. Traffic for voice services is designated for IP 
subnet 172.16.1.0/24, video for 192.168.1.0/24 and data for 10.1.1.0/24. The Switch can then 
be configured to group incoming traffic based on the source IP subnet of incoming frames.    
You configure a subnet based VLAN with priority 6 and VID of 100 for traffic received from 
IP subnet 172.16.1.0/24 (voice services). You also have a subnet based VLAN with priority 5 
and VID of 200 for traffic received from IP subnet 192.168.1.0/24 (video services). Lastly, 
you configure VLAN with priority 3 and VID of 300 for traffic received from IP subnet 
10.1.1.0/24 (data services). All untagged incoming frames will be classified based on their 
source IP subnet and prioritized accordingly. That is video services receive the highest priority 
and data the lowest. 

Figure 36   Subnet Based VLAN Application Example 

Apply

Click Apply to save your changes to the Switch’s run-time memory. The Switch 

loses these changes if it is turned off or loses power, so use the Save link on the 

top navigation panel to save your changes to the non-volatile memory when you 

are done configuring.

Cancel

Click Cancel to begin configuring this screen afresh.

Table 18   Advanced Application > VLAN > VLAN Port Setting  (continued)