Chapter 9 VLAN
XS1930 Series User’s Guide
116
9.1.2.2 Port VLAN Trunking
Enable
VLAN Trunking
on a port to allow frames belonging to unknown VLAN groups to pass through
that port. This is useful if you want to set up VLAN groups on end devices without having to configure the
same VLAN groups on intermediary devices.
Refer to the following figure. Suppose you want to create VLAN groups 1 and 2 (V1 and V2) on devices
A and B. Without
VLAN Trunking
, you must configure VLAN groups 1 and 2 on all intermediary switches C,
D and E; otherwise they will drop frames with unknown VLAN group tags. However, with
VLAN Trunking
enabled on a port(s) in each intermediary switch you only need to create VLAN groups in the end
devices (A and B). C, D and E automatically allow frames with VLAN group tags 1 and 2 (VLAN groups
that are unknown to those switches) to pass through their VLAN trunking port(s).
Figure 85
Port VLAN Trunking
9.1.2.3 VLAN Priority
At the time of writing, you can create static VLANs, Voice VLANs and Vendor ID-based VLANs on the
Switch when the VLAN type is set to
802.1Q
. When a packet is received, the Switch processes the VLAN
rules in sequence. The sequence (priority) of the VLANs is:
1
Vendor ID Based VLAN
2
Voice VLAN
If the packet matches a VLAN rule that has a higher priority, for example, an entry with weight 250 in the
vendor ID to VLAN mapping table, the Switch assigns the corresponding VLAN ID to the packet and
stops checking the subsequent VLAN rules.
VLAN Administrative
Control
Registration Fixed
Fixed registration ports are permanent VLAN members.
Registration
Forbidden
Ports with registration forbidden are forbidden to join the specified
VLAN.
Normal Registration
Ports dynamically join a VLAN using GVRP.
VLAN Tag Control
Tagged
Ports belonging to the specified VLAN tag all outgoing frames
transmitted.
Untagged Ports
belonging
to the specified VLAN don't tag all outgoing frames
transmitted.
VLAN Port
Port VID
This is the VLAN ID assigned to untagged frames that this port
received.
Acceptable Frame
Type
You may choose to accept both tagged and untagged incoming
frames, just tagged incoming frames or just untagged incoming
frames on a port.
Ingress filtering
If set, the Switch discards incoming frames for VLANs that do not
have this port as a member
Table 48 IEEE 802.1Q VLAN Terminology (continued)
VLAN PARAMETER
TERM
DESCRIPTION