Reference Guide

The only way to remove an interface from the Default VLAN is to place the interface in Default mode by
using the no switchport command in INTERFACE mode.
Assigning an IP Address to a VLAN
VLANs are a Layer 2 feature. For two physical interfaces on different VLANs to communicate, assign an IP
address to the VLANs to route traffic between the two interfaces.
The shutdown command in INTERFACE mode does not affect Layer 2 traffic on the interface; the
shutdown command only prevents Layer 3 traffic from traversing over the interface.
NOTE: You cannot assign an IP address to the Default VLAN (VLAN 1). To assign another VLAN ID to
the Default VLAN, use the
default vlan-id vlan-id command.
In Dell Networking OS, you can place VLANs and other logical interfaces in Layer 3 mode to receive and
send routed traffic. For more information, refer to Bulk Configuration.
To assign an IP address, use the following command.
• Configure an IP address and mask on the interface.
INTERFACE mode
ip address ip-address mask [secondary]
– ip-address mask — Enter an address in dotted-decimal format (A.B.C.D) and the mask must be
in slash format (/24).
– secondary — This is the interface’s backup IP address. You can configure up to eight secondary
IP addresses.
Enabling Null VLAN as the Default VLAN
In a Carrier Ethernet for Metro Service environment, service providers who perform frequent
reconfigurations for customers with changing requirements occasionally enable multiple interfaces, each
connected to a different customer, before the interfaces are fully configured.
This presents a vulnerability because both interfaces are initially placed in the native VLAN, VLAN 1, and
for that period customers are able to access each other's networks. Dell Networking OS has a Null VLAN
to eliminate this vulnerability. When you enable the Null VLAN, all ports are placed into it by default, so
even if you activate the physical ports of multiple customers, no traffic is allowed to traverse the links
until each port is place in another VLAN.
To enable Null VLAN, use the following command.
• Disable the default VLAN, so that all ports belong to the Null VLAN until configured as a member of
another VLAN.
CONFIGURATION mode
default-vlan disable
Default: the default VLAN is enabled (no default-vlan disable).
Virtual LANs (VLANs)
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