Enterasys Networks 6000 - Manual (Page 91)

The Device View
2-72 Managing the Module
If a port receives a tagged frame that specifies a VLAN other than the one assigned to the
port, the switch will dynamically associate that frame’s source address and VLAN with
the port (i.e., add that frame’s VLAN to the receiving port’s egress list). Dynamically
learned VLANs are subject to the same aging rules as source addresses (e.g., if a tagged
frame belonging to a dynamically learned VLAN is not received by the port within the
switch’s aging time, the transmitting station’s source address and VLAN will be aged out
for that port; no unknown destination frames belonging to the station’s VLAN will be
transmitted through the port until the VLAN is dynamically learned once again). Only
tagged frames can cause the switch to dynamically change a port’s egress list.
802.1Q Port Types
Each 802.1Q switch port is assigned a mode of operation. Port types include:
1Q Trunk
If VLAN membership is to apply to users across several switches, ports used to connect
802.1Q-aware devices are configured to use 1Q Trunk mode. In this mode, all frames
(except BPDUs) are transmitted with a tag header included in the frame, allowing VLAN
frames to maintain their VLAN ID across multiple switches. Any untagged frames
received by the port are dropped. 1Q Trunk ports are configured to be members of all
VLANs.
1d Trunk
This mode allows a port to transmit to a traditional (802.1d) switch fabric. These ports
transmit only untagged frames, and the switch expects to receive only untagged traffic
through the port. 1d Trunk ports are configured to be members of all VLANs. This mode
can be used to share a connection among multiple VLANs (e.g., sharing a server between
two or more separate VLANs).
Hybrid
Hybrid mode (enabled by default) allows a port to receive and transmit both tagged and
untagged frames. In this mode, the port will be a member of its statically assigned VLAN,
as well as any dynamically learned VLANs (remember, dynamically learned VLANs are
subject to the same aging rules as source addresses).
Configuring Your 802.1Q VLANS
Before you can define and configure 802.1Q port-based VLANs on your device, you must
activate the device’s 802.1Q operational mode; this operation can be performed using
Local Management or the MIB Tools application. Using MIB Tools, 802.1Q mode can be
activated through the Container MIB’s Logical Entry Table (contLogicalEntryTable).
When the 802.1Q component is activated, the device will automatically reset, and begin
operating in 802.1Q mode.
Refer to your device’s Local Management documentation for instructions on activating a
device’s 802.1Q operational mode via Local Management. For details on the MIB Tools
application, refer to your Element Manager Tools Guide.