NOTE: You cannot assign an IP address to the Default VLAN. To assign an IP address to a VLAN that is currently theDefault VLAN, create another VLAN and assign it to be the Default VLAN. For more information about assigning IPaddresses, refer to Assigning an IP Address to a VLAN.• Untagged interfaces must be part of a VLAN. To remove an untagged interface from the Default VLAN, create another VLANand place the interface into that VLAN. Alternatively, use the no switchport command, and Dell Networking OS removes theinterface from the Default VLAN.• A tagged interface requires an additional step to remove it from Layer 2 mode. Because tagged interfaces can belong to multipleVLANs, remove the tagged interface from all VLANs using the no tagged interface command. Only after the interface isuntagged and a member of the Default VLAN can you use the no switchport command to remove the interface from Layer2 mode. For more information, refer to VLANs and Port Tagging.Example of Configuring an Interface for Layer 2 Belonging to the Default VLANDell(conf)#interface tengigabitethernet 1/2Dell(conf-if)#no shutDell(conf-if)#switchportDell(conf-if)#show config!interface TenGigabitEthernet 1/2no ip addressswitchportno shutdownDell(conf-if)#endDell#show vlanCodes: * - Default VLAN, G - GVRP VLANsNUM Status Q Ports* 1 Active U Te 1/2T Te 1/1Port-Based VLANsPort-based VLANs are a broadcast domain defined by different ports or interfaces. In Dell Networking OS, a port-based VLAN cancontain interfaces from different line cards within the chassis. Dell Networking OS supports 4094 port-based VLANs.Port-based VLANs offer increased security for traffic, conserve bandwidth, and allow switch segmentation. Interfaces in differentVLANs do not communicate with each other, adding some security to the traffic on those interfaces. Different VLANs cancommunicate between each other by means of IP routing. Because traffic is only broadcast or flooded to the interfaces within aVLAN, the VLAN conserves bandwidth. Finally, you can have multiple VLANs configured on one switch, thus segmenting the device.Interfaces within a port-based VLAN must be in Layer 2 mode and can be tagged or untagged in the VLAN ID.VLANs and Port TaggingTo add an interface to a VLAN, the interface must be in Layer 2 mode. After you place an interface in Layer 2 mode, the interface isautomatically placed in the Default VLAN.Dell Networking OS supports IEEE 802.1Q tagging at the interface level to filter traffic. When you enable tagging, a tag header isadded to the frame after the destination and source MAC addresses. That information is preserved as the frame moves through thenetwork. The following example shows the structure of a frame with a tag header. The VLAN ID is inserted in the tag header.Figure 112. Tagged Frame FormatThe tag header contains some key information that Dell Networking OS uses:Virtual LANs (VLANs) 739
