Chapter 9 VLAN
MGS3700-12C User’s Guide
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9.6 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.
Ingress Check If this check box is selected for a port, the Switch discards incoming
frames for VLANs that do not include this port in its member set.
Clear this check box to disable ingress filtering.
PVID A PVID (Port VLAN ID) is a tag that adds to incoming untagged frames
received on a port so that the frames are forwarded to the VLAN group
that the tag defines.
Enter a number between 1and 4094 as the port VLAN ID.
GVRP Select this check box to allow GVRP on this port.
Acceptable
Frame Type
Specify the type of frames allowed on a port. Choices are All, Tag Only
and Untag Only.
Select All from the drop-down list box to accept all untagged or tagged
frames on this port. This is the default setting.
Select Tag Only to accept only tagged frames on this port. All untagged
frames will be dropped.
Select Untag Only to accept only untagged frames on this port. All
tagged frames will be dropped.
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.
Isolation Select this to allows this port to communicate only with the CPU
management port and the ports on which the isolation feature is not
enabled.
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)
LABEL DESCRIPTION