Allied Telesis AT-S39 - Manual (Page 158)

Section II: Local and Telnet Management
158
Caution
The non-802.1Q-Compliant Multiple VLAN mode does not protect
the switch from VLAN leakage. If a packet arrives on the uplink port
containing a destination MAC address not in the MAC address table,
the switch will broadcast the packet out all ports, except the uplink
port. This means that all end nodes on the switch will receive the
packet.
Preserving
User-
Configured
VLANs
When the VLAN mode is set to either of the multiple VLAN mode, user-
configured VLAN definitions cannot be created or modified. However,
the software preserves user-configured VLANs that were configured
before multiple VLAN mode was enabled. When the user switches back
to user-configured VLANs mode, the software automatically enables the
user-configured VLANs with the pre-existing configuration.
Uplink VLANs -
Multiple VLANs
Mode
Management
Although both multiple VLAN modes support remote management of
the switch via a management VLAN, the management VLAN is
designated by default to the uplink port and you are not allowed to
modify it. If you are in a multiple VLAN mode and you select the
Management VLAN parameter in the VLAN menu, the following
message is displayed:
Management VLAN can not be changed in Multiple VLANs
mode
Client_VLAN_23 23 23,15
Client_VLAN_24 24 24,15
Client_VLAN_25 25 25,15
Client_VLAN_26 26 26,15
VLAN Name VID Untagged Port Tagged Port