lan9117 Standard Microsystems Corp., lan9117 Datasheet - Page 25

• Manufacturer Part Number: lan9117
• Description: Lan9117 High-performance Single-chip 10/100 Non-pci Ethernet Controller
• Manufacturer: Standard Microsystems Corp.

High Performance Single-Chip 10/100 Non-PCI Ethernet Controller
Datasheet
SMSC LAN9117
LAN Switch #2
AAA
Network efficiency: Allows shielding one system resource from traffic not meant for that resource. A
workstation in one VLAN is shielded from traffic on another VLAN, increasing that workstation’s
efficiency.
Broadcast containment: Leakage of broadcast frames from one VLAN to another is prevented.
When the members of a VLAN are not located on the same physical medium, the VLAN uses a tag
to help it determine how to forward the frame from one member to another. The tag structure was
proprietary until the IEEE released a supplement to 802.3 defining the VLAN frame structure, including
the tag. This new frame structure for VLAN is depicted in Figure 3.2, "VLAN Frame".
VLAN 3
BBB
Address
GGG
AAA
BBB
CCC
DDD
EEE
HHH
FFF
CCC
VLAN Config Data
LAN Switch #1
Figure 3.1 VLAN Topology
VLAN #
VLAN 3
VLAN 3
VLAN 3
VLAN 2
VLAN 2
VLAN 2
VLAN 1
VLAN 1
DATASHEET
DDD
25
VLAN 2
EEE
FFF
LAN Switch #3
GGG
VLAN 1
Revision 1.5 (07-11-08)
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