Access Ports And Trunk Ports (802.1P And 802.1Q Support) - HP procurve 8100fl series Management And Configuration Manual

VLAN Configuration

Access Ports and Trunk Ports (802.1P and 802.1Q support)

6-4
Access Ports and Trunk Ports (802.1P
and 802.1Q support)
The ports of the 8100fl switch can be classified into two types, based on VLAN
functionality: access ports and trunk ports. By default, a port is an access
port. An access port can belong to at most one VLAN. Frames transmitted out
of an access port contain no special information about the VLAN to which
they belong. These frames are classified as belonging to a particular VLAN
based on the VLAN configured on the receiving port.
Trunk ports (802.1Q) are usually used to connect one VLAN-aware switch to
another. They carry traffic belonging to several VLANs.
For example, suppose that two separate ProCurve 8100fl switches (switch A
and switch B) are both configured with VLANs V1 and V2. Then a frame
arriving at a port on switch A must be sent to switch B, if the frame belongs
to VLAN V1 or to VLAN V2. Thus the ports on switch A and B which connect
the two switches together must belong to both VLAN V1 and VLAN V2. Also,
when these ports receive a frame, they must be able to determine whether the
frame belongs to VLAN V1 or to VLAN V2. This is accomplished by "tagging"
the frames, that is, by prepending information to the frame in order to identify
the VLAN to which the frame belongs.
In the 8100fl switch, trunk ports normally transmit and receive tagged frames
only. (The format of the tag is specified by the IEEE 802.1Q standard.) If you
configure Spanning Tree Protocol (see
untagged frames. You can also configure native VLANs to enable 802.1Q trunk
ports to receive and transmit untagged frames by entering.
ProCurve(config-if)#switchport trunk-native-vlan <VLAN ID>
page 9-15), frames are transmitted as