Vlan Types - HP A6600 Configuration Manual

Figure 30 The format of a traditional Ethernet frame
IEEE 802.1Q inserts a four-byte VLAN tag after the DA&SA field, as shown in
Figure 31 The position and format of VLAN tag
A VLAN tag comprises the following fields: TPID, priority, CFI, and VLAN ID.
The 16-bit TPID field with a value of 0x8100 indicates that the frame is VLAN-tagged.
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The 3-bit priority field indicates the 802.1p priority of the frame.
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The 1-bit CFI field specifies whether the MAC addresses are encapsulated in the standard format
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when packets are transmitted across different media. A value of 0 indicates that MAC addresses are
encapsulated in the standard format. A value of 1 indicates that MAC addresses are encapsulated
in a non-standard format. The value of the field is 0 by default.
The 12-bit VLAN ID field identifies the VLAN the frame belongs to. The VLAN ID range is 0 to 4095.
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As 0 and 4095 are reserved, a VLAN ID actually ranges from 1 to 4094.
A network device handles an incoming frame depending on whether the frame is VLAN tagged and the
value of the VLAN tag, if any.
The Ethernet II encapsulation format is used here. Besides the Ethernet II encapsulation format, other
encapsulation formats, including 802.2 LLC, 802.2 SNAP, and 802.3 raw, are also supported by
Ethernet. The VLAN tag fields are also added to frames encapsulated in these formats for VLAN
identification.
For a frame with multiple VLAN tags, the router handles it according to its outer-most VLAN tag and
transmits its inner VLAN tags as payload.

VLAN types

Implement VLANs based on the following criteria:
Port
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MAC address
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Protocol
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IP subnet
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Policy
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Other criteria
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This chapter covers port-based VLAN, MAC-based VLAN, protocol-based VLAN, and IP-based VLAN. The
port-based VLAN implementation is the basis of all other VLAN implementations. To use any other VLAN
implementations, you must configure port-based VLAN settings.
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Figure 31.