Configuring Port-Based Vlans; Introduction To Port-Based Vlan - HP 6125G Configuration Manual

Configuring port-based VLANs

Introduction to port-based VLAN

Port-based VLANs group VLAN members by port. A port forwards traffic for a VLAN only after it is
assigned to the VLAN.
Port link type
You can configure the link type of a port as access, trunk, or hybrid. The link types use the following
VLAN tag handling methods:
An access port belongs to only one VLAN and sends traffic untagged. It is usually used to connect
•
a terminal device unable to identify VLAN tagged-packets or when separating different VLAN
members is unnecessary.
A trunk port can carry multiple VLANs to receive and send traffic for them. Except traffic from the
•
port VLAN ID (PVID), traffic sent through a trunk port will be VLAN tagged. Usually, ports that
connect network devices are configured as trunk ports.
Like a trunk port, a hybrid port can carry multiple VLANs to receive and send traffic for them. Unlike
•
a trunk port, a hybrid port allows traffic of all VLANs to pass through VLAN untagged. You can
configure a port connected to a network device or user terminal as a hybrid port.
PVID
By default, VLAN 1 is the PVID for all ports. You can configure the PVID for a port as required.
When you configure the PVID on a port, use the following guidelines:
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. 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 use the undo vlan command to remove the VLAN that an access port resides in, the PVID
of the port changes to VLAN 1. The removal of the VLAN specified as the PVID of a trunk or hybrid
port, however, does not affect the PVID setting on the port.
When you configure a PVID, follow these guidelines:
Do not set the voice VLAN as the PVID of a port in automatic voice VLAN assignment mode. For
•
information about voice VLAN, see
HP recommends that you set the same PVID ID for local and remote ports.
•
Make sure that a port permits the traffic from its PVID to pass through. Otherwise, when the port
•
receives frames tagged with the PVID or untagged frames, the port drops these frames.
The following table shows how ports of different link types handle frames:
Port type
Actions (in the inbound direction)
Untagged frame
"Configuring a voice VLAN."
Tagged frame
104
Actions (in the outbound
direction)