Vlan Classification; Configuring Basic Vlan Attributes - 3Com MSR 50 Series Configuration Manual

VLAN Classification

Configuring Basic
VLAN Attributes
The Priority field, three bits in length, indicates the 802.1p priority of a packet.
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For information about packet priority, refer to
1675.
The CFI field, one bit in length, specifies whether or not the MAC addresses are
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encapsulated in standard format when packets are transmitted across different
medium. With the field set to 0, MAC addresses are encapsulated in standard
format; with the field set to 1, MAC addresses are encapsulated in
non-standard format. The filed is 0 by default.
The VLAN ID field, 12 bits in length and with its value ranging from 0 to 4095,
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identifies the ID of the VLAN a packet belongs to. As VLAN IDs of 0 and 4095
are reserved by the protocol, the actual value of this field ranges from 1 to
4094.
A network device determines the VLAN to which a packet belongs to by the VLAN
ID field the packet carries. The VLAN tag determines the way a packet is
processed. For more information, refer to
page 491.
n
The frame format mentioned here is that of Ethernet II. Besides Ethernet II
encapsulation, other types of encapsulation, including 802.2 LLC, 802.2 SNAP,
and 802.3 raw are also supported. The VLAN tag fields are also added to packets
adopting these encapsulation formats for VLAN identification.
Based on different criteria, VLANs can be classified into different categories. The
following types are the most commonly used:
Port-based
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MAC address-based
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Protocol-based
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IP-subnet-based
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Policy-based
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Other types
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This chapter covers port-based VLAN, MAC-address-based VLAN, protocol-based
VLAN, and IP-subnet-based VLAN. For ports with all these types of VLANs created
on them, packets of different VLANs are identified in this order by default:
MAC-address-based VLAN, IP-subnet-based VLAN, protocol-based VLAN, and
port-based VLAN.
Follow the following steps to configure basic VLAN attributes:
To do...
Enter system view
Create VLANs

Configuring Basic VLAN Attributes

"Introduction to Port-Based VLAN" on
Use the command...
system-view
vlan { vlan-id1 [ to
vlan-id2 ] | all }
"Priority Mapping" on page
Remarks
-
Optional
Using this command can create multiple
VLANs.
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