HP 1920 Gigabit Ethernet Switch Series User Manual page 149

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.
HP 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
In the inbound
direction for an
untagged frame
In the inbound
direction for a
tagged frame
In the outbound
direction
Access
Tags the frame with the
PVID tag.
•
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.
Removes the VLAN tag
and sends the frame.
Trunk
Checks whether the PVID is permitted on the port:
•
If yes, tags the frame with the PVID tag.
•
If not, drops the frame.
•
Receives the frame if its VLAN is permitted on the port.
•
Drops the frame if its VLAN is not permitted on the port.
•
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.
136
Hybrid
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.