HP 9304m Installation And Getting Started Manual page 203

Installation and Getting Started Guide
Figure 7.4 Packet containing HP's 802.1QVLAN tag
Untagged Packet Format
6 bytes 6 bytes
Destination Source
Address Address
6 bytes 6 bytes
Destination Source
Address Address
802.1q Tagged Packet Format
6 bytes 6 bytes
Destination Source
Address Address
6 bytes 6 bytes
Destination Source
Address Address
Octet 1
Tag Protocol Id (TPID)
NOTE: You cannot configure a port to be a member of the default port-based VLAN and another port-based
VLAN at the same time. Once you add a port to a port-based VLAN, the port is no longer a member of the default
VLAN. The port returns to the default VLAN only if you delete the other VLAN(s) that contains the port.
If you configure a VLAN that spans multiple devices, you need to use tagging only if a port connecting one of the
devices to the other is a member of more than one port-based VLAN. If a port connecting one device to the other
is a member of only a single port-based VLAN, tagging is not required.
If you use tagging on multiple devices, each device must be configured for tagging and must use the same tag
value. In addition, the implementation of tagging must be compatible on the devices. The tagging on all HP
devices is compatible with other HP devices.
7 - 6
2 bytes Up to 1500 bytes
Type Data
Field Field
2 bytes Up to 1496 bytes
Length Data
Field Field
2 bytes 4 bytes 2 bytes Up to 1500 bytes
Type 802.1q Type Data
Field Tag Field Field
2 bytes 4 bytes 2 bytes Up to 1496 bytes
Length 802.1q Length Data
Field Tag Field Field
Octet 2
1 2 3 4 5 6 7 8
802.1p
VLAN ID (12 bits)
(3 bits)
4 bytes
CRC
4 bytes
CRC
Up to 1500 bytes 4 bytes
Data CRC
Field
Up to 1496 bytes 4 bytes
Data CRC
Field
Octet 4
Ethernet II
IEEE 802.3
4 bytes
CRC
Ethernet II Ethernet II with 802.1q tag
4 bytes
CRC
IEEE 802.3 with 802.1q tag
IEEE 802.3