VLAN Considerations

Be aware of the following issues when configuring VLANs:

• If you set Trunk Mode to Clear, you must set the VLAN Binding Type to Static (default).
• The switch supports a feature called Automatic VLAN Creation for tagged frames. When this feature is enabled, the switch creates new VLANs when it receives packets from previously unknown VLANs. Vlans can be created automatically without manually creating the VLAN on each switch.
• Automatic VLAN Creation does not work on an 80-series supervisor module (M8000R-SUP) if the Port default VLAN is set to discard.
• If you enable Automatic VLAN Creation and set VLAN Binding type to Bind to Received, make sure that you set the binding type before enabling Automatic VLAN Creation or else the port may not be automatically added to the VLAN.
• Assigning one of the ports of a 48-port module to a VLAN for which there exists IP interface will force that interface to be in the UP state, even when there is no physical connection to the module.