H3C Technologies H3C WX5500E Series Access Controllers - Manual (Page 131)

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PVID
By default, VLAN 1 is the PVID for all ports. You can change the PVID for a port, as required.
Use the following guidelines when you configure the PVID on a port:
• An access port can join only one VLAN. The VLAN to which the access port belongs is the PVID of
the port.
• A trunk or hybrid port can join multiple VLANs, and you can configure a PVID for the port.
• You can use a nonexistent VLAN as the PVID for a hybrid or trunk port, but not for an access port.
After you delete the VLAN that an access port resides in, the PVID of the port changes to VLAN 1.
However, deleting the VLAN specified as the PVID of a trunk or hybrid port does not affect the PVID
setting on the port.
• Do not set the voice VLAN as the PVID of a port in automatic voice VLAN assignment mode. For
information about voice VLAN, see "
Configuring a voice VLAN ."
• H3C recommends that you set the same PVID for local and remote ports.
• Make sure a port permits its PVID. Otherwise, when the port receives frames tagged with the PVID
or untagged frames, the port drops these frames.
Frame handling methods
The following table shows how ports of different link types handle frames:
Actions Access Trunk Hybrid
In the inbound
direction for an
untagged frame
Tags the frame with the
PVID tag.
Checks whether the PVID is permitted on the port:
• If yes, tags the frame with the PVID tag.
• If not, drops the frame.
In the inbound
direction for a
tagged frame
• Receives the frame if
its VLAN ID is the
same as the PVID.
• Drops the frame if its
VLAN ID is different
from the PVID.
• Receives the frame if its VLAN is permitted on the port.
• Drops the frame if its VLAN is not permitted on the port.
In the outbound
direction Removes the VLAN tag
and sends the frame.
• Removes the tag and sends
the frame if the frame carries
the PVID tag and the port
belongs to the PVID.
• Sends the frame without
removing the tag if its VLAN is
carried on the port, but is
different from the PVID.
Sends the frame if its VLAN
is permitted on the port. The
frame is sent with the VLAN
tag removed or intact
depending on your
configuration with the port
hybrid vlan command. This
is true of the PVID.
Configuration guidelines
When you configure VLANs, follow these guidelines:
• As the default VLAN, VLAN 1 can be neither created nor removed manually.
• You cannot manually create or remove VLANs reserved for special purposes.
• Dynamic VLANs cannot be removed on the page for removing VLANs.