D-Link DES-3624 - Switch - Stackable User manual - Vlan Segmentation
Stackable NWay Ethernet Switch User’s Guide
VLAN Segmentation
Take for example a packet that is transmitted by a machine on
Port 1 that is a member of VLAN 2 and has the Port VLAN ID
number 2 (PVID=2). If the destination lies on another port
(found through a normal forwarding table lookup), the switch
then looks to see if the other port (Port 10) is a member of
VLAN 2 (and can therefore receive VLAN 2 packets). If port 10
is not a member of VLAN 2, then the packet will be dropped by
the switch and will not reach it’s destination. If Port 10 is a
member of VLAN 2, the packet will go through. This selective
forwarding feature based on VLAN criteria is how VLANs
segment networks. The key point being that Port 1 will only
transmit on VLAN 2, because it’s Port VLAN ID number is 2
(PVID=2).
Sharing Resources Across VLANs
Network resources such as printers and servers however, can
be shared across VLANs. This is achieved by setting up
overlapping VLANs as shown in the diagram below.
VLAN 1
Port
VIDs = 1
VLAN 2
Port
VIDs = 2
Port
PVID = 3
VLAN 3
1 2 3 4
5 6 7 8
9 10 11 12
Graphics
Workstations
Workstations
Network
Server
Figure 5-4. Example of typical VLAN configuration
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Switch Management Concepts