Microchip Technology Microsemi PDS-408G, Web Management User Manual, Page: 36 / 99

VLAN General
Microsemi PDS-408G Web Management User Guide Ver. 1.0.1, 03-2019
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6 VLAN
6.1 General
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VLAN Access - VLAN is a mean to split Switch ports into support groups while each group is
totally isolated from the other as if we are using two or more independent Switches. Such
splitting is done by assigning different VLAN-IDs to various groups of ports, each group is
assigned a different VLAN-ID and the ports for each group are configured as Access ports,
meaning that VLAN tagging and port splitting is done internally by the switch. The packets
transmitted over the Access ports are the normal Ethernet ports with no VLAN tagging.
•
VLAN Trunk – VLAN Trunk port configuration allows multiple VLAN-IDs to transfer over the
same Ethernet cable or local LAN network with absolute separation between the VLANs
transferring over the same infrastructure. A good analogy will be a highway with several lanes
having physical separation between each lane, preventing from a car to switch lanes although
all the cars are traveling from one side of the highway to the other.
6.1.1 Supported VLAN types
The switch supports single 802.1Q VLAN tagging and double 802.1Q VLAN tagging also known as
QinQ or 802.1ad. Switch ports with no external VLAN tagging are referred to as Access-Ports. Switch
Ports with external single VLAN tagging are referred to as Trunk C-Ports (C=customer VLAN). Ports
with double VLAN tagging are referred to as Trunk S-Ports (S=Service VLAN), as an internet service
provider may encapsulate customer VLAN on top of its own VLAN, resulting in double VLAN tagging.
Figure 6-1: single and double VLAN tagging packet format
6.1.2 VLAN typing syntax
Individual VLAN elements are separated by commas. Ranges are specified with a dash separating the
lower and upper bound. The following example
1,10-13,200,300 will create VLANs 1, 10, 11, 12, 13,
200, and 300.
6.2 VLAN – Configuration
The VLAN configuration page consists of a global section and per port VLAN configuration.
NOTE:
NOTE – The next section contains several VLAN configuration examples which should make
VLAN configuration understanding easier.
Destination MAC
6 BYTE
Source MAC
6 BYTE
802.1Q Header
4 BYTE
Payload
TPID
2-BYTE
0x8100
VLAN-ID
2-BYTE
1-4095
Destination MAC
6 BYTE
Source MAC
6 BYTE
802.1Q Header
4 BYTE
Payload
TPID
2-BYTE
0x88A8
VLAN-ID
2-BYTE
1-4095
802.1Q Header
4 BYTE
TPID
2-BYTE
0x8100
VLAN-ID
2-BYTE
1-4095
C-Tag
S-Tag