ZyXEL Communications ES-2048, User Manual

Page: 88 / 306

Chapter 8 VLAN
ES-2048 User’s Guide
88
8.6 Subnet Based VLANs
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 35 Subnet Based VLAN Application Example
VLAN Trunking Enable VLAN Trunking on ports connected to other switches or routers (but not
ports directly connected to end users) to allow frames belonging to unknown VLAN
groups to pass through the Switch.
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 17 Advanced Application > VLAN > VLAN Port Setting (continued)
LABEL DESCRIPTION
10.1.1.0/24
192.168.1.0/24 172.16.1.0/24
Internet
VID = 100 VID = 200
VID = 300
Untagged
Frames
Tagged Frames