3Com 3500 - Manual (Page 364)

364 C HAPTER 14: V IRTUAL LAN S (VLAN S )
✓ 3500
✓ 9000
✓ 9400
✓
3900
✓
9300
bridge vlan mode Determines whether data with a unicast MAC address can be forwarded
between VLANs.
Valid Minimum Abbreviation
b v mode
Important Considerations
■
Select a VLAN mode as follows:
■
allOpen — Use this less restrictive mode if you do not have
security issues concerning the forwarding of data between VLANs.
It is the default VLAN mode for all VLANs that you create. It permits
data with a unicast MAC address to be forwarded between VLANs.
The allOpen mode implies that the system uses a single bridge
address table for all of the VLANs on the system.
■
allClosed — Use this restrictive mode if you are concerned about
security between VLANs. Data cannot be forwarded between
VLANs but can still be routed between VLANs. This mode implies
that each VLAN that you create has its own address table.
■
For the CoreBuilder 3500 system and CoreBuilder 9000 Layer 3
modules, if you are using allClosed mode and STP (with multiple
routes to a destination), you can also use the command “bridge vlan
stpMode” to disable STP blocking for a specified VLAN.
■
For the CoreBuilder 9000, set a VLAN mode for each switching
module and the switch fabric module.
■
Changing this mode removes all VLANs and redefines the default
VLAN.
■
Before you issue this command to change the mode, you must remove
all routing interfaces, including router port IP interfaces. If routing
interfaces are defined, the system displays this message:
could not change configured VLAN mode - interface in
use by client.
Options
Prompt Description Possible Values [Default]
VLAN mode Selected VLAN mode for the entire
system
■
allOpen
■
allClosed
allOpen
(factory
default), or
current value