Digisol DG-FS4528P, Management Manual

Page: 321 / 973

C
HAPTER
13 | VLAN Configuration
IEEE 802.1Q VLANs
– 321 –
boundary ports to prevent advertisements from being propagated, or
forbid those ports from joining restricted VLANs.
N
OTE
:
If you have host devices that do not support GVRP, you should
configure static or untagged VLANs for the switch ports connected to these
devices (as described in "Adding Static Members to VLANs" ). But you can
still enable GVRP on these edge switches, as well as on the core switches in
the network.
Figure 154: Using GVRP
Forwarding Tagged/Untagged Frames
If you want to create a small port-based VLAN for devices attached directly
to a single switch, you can assign ports to the same untagged VLAN.
However, to participate in a VLAN group that crosses several switches, you
should create a VLAN for that group and enable tagging on all ports.
Ports can be assigned to multiple tagged or untagged VLANs. Each port on
the switch is therefore capable of passing tagged or untagged frames.
When forwarding a frame from this switch along a path that contains any
VLAN-aware devices, the switch should include VLAN tags. When
forwarding a frame from this switch along a path that does not contain any
VLAN-aware devices (including the destination host), the switch must first
strip off the VLAN tag before forwarding the frame. When the switch
receives a tagged frame, it will pass this frame onto the VLAN(s) indicated
by the frame tag. However, when this switch receives an untagged frame
from a VLAN-unaware device, it first decides where to forward the frame,
and then inserts a VLAN tag reflecting the ingress port’s default VID.
Port-based VLAN
1
2
9 3 4
10 11
12
13
14
5 6 7 8
15 16
18
19