User guide

4-2 B
LACK
D
IAMOND
U
SER
G
UIDE
V
IRTUAL
LAN
S
(VLAN
S
)
• VLANs provide extra security.
Devices within each VLAN can only communicate with member devices in the same
VLAN. If a device in VLAN Marketing must communicate with devices in VLAN
Sales, the traffic must cross a routing device.
• VLANs ease the change and movement of devices.
With traditional networks, network administrators spend much of their time dealing
with moves and changes. If users move to a different subnetwork, the addresses of
each endstation must be updated manually.
For example, with a VLAN, if an endstation in VLAN Marketing is moved to a port
in another part of the network, and retains its original subnet membership; you must
only specify that the new port is in VLAN Marketing.
T
YPES OF
VLAN
S
The BlackDiamond supports a maximum of 256 VLANs. VLANs can be created
according to the following criteria:
• Physical port
• 802.1Q tag
• Ethernet, LLC SAP, or LLC/SNAP Ethernet protocol type
• A combination of these criteria
P
ORT
-B
ASED
VLAN
S
In a port-based VLAN, a VLAN name is given to a group of one or more ports on the
switch. A port can be a member of only one port-based VLAN.
For example, on the G6X module in Figure 4-1, ports 1, 2, and 5 are part of VLAN
Marketing; ports 3 and 4 are part of VLAN Sales; and port 6 is in VLAN Finance. On the
F32T module, ports 1 through 4 and ports 17 through 20 are part of VLAN Marketing;
ports 9 through 12 and ports 21 through 24 are part of VLAN Sales; and ports 9 through
16 and ports 25 through 32 are part of VLAN Finance.